I went through the exact same process as you. I was looking for a jeep which i could use as a daily driver and also outfit to camp off road. I arrived at the Liberty CRD. I will give you a rundown of my experience both good and bad.
History
I purchased on with about 18K miles on it at the end of 2009. It was a lease vehicle and in very good shape. I sold it at the end of 2010 with 42K miles. S in one year i put 24k miles. Lots of daily driving and several trips. One trip i put on 3k alone. I live in the SW so going on trips tends to yield many freeway miles before you get to the trail. I used to have a 2006 LJ rubicon (which i could totally kick myself for selling). I missed the LJ rubicon so much, which factored into why i sold the liberty and went to a 4 door rubicon.
Modifications
Frankenlift II 2.5" lift - OME heavy springs front and back with OME shocks. Easy install - one afternoon. After install got firestone lifetime alignment. Did 3 alignments over the 24k i owned it.
BFG all terrain load range E - mainly wanted strong sidewalls for off road.
Skid plates front to back - all mopar. Went on real easy, about an hour total.
I always traveled with a maggiolina airland small XL on the top of the liberty. I absolutely love the airland. I highly recommend it. Made the weekend camping trip much better for us. It sets up in a snap and packs in a snap. You can keep all your sleeping stuff up there and it is always ready to go.
What i liked:
The engine is great and has really good torque. I loved the performance in the mountains, what a difference. It keeps speed at high elevation up steep grades better than most gas vehicles.
Off road it was very good for a liberty. I believe all the torque made a huge difference. It was like a tractor in 4WL and pulled over everything, never had an issue with wheel slip when opposite tires were in the air, such as when crossing a deep obsticle at an angle. The OME gave good clearance and i was able to go with people that had lifted TJ's with 33's and keep up with them no problem. Obviously you need to drive smart, which makes the most difference.
Road handling with the OME was very nice. When it was unloaded it was a pretty rough ride, but it cornered very well. Once fully loaded it drove very smooth. I took about two off road trips and 3k miles for the suspension to soften up a bit. At first it was very harsh IMHO.
What I did not like
The fuel economy is not what it is cracked up to be. My EVIC always said 24mpg with the lift, but calculated at the fuel pump and mileage it was 19-20mpg. Without the lift EVIC said 30mpg and at the pump it was 25-26mpg average. I attribute the difference due tire size change. With the factory setup my speedo would be about 4mph off. Once i put the larger BFG on i was only 1mph off. This was tested, by comparing to my old vehicle and drive to work, gps speed, and radar. All three told the same story. The only time i every pulled an actual 24mpg with the lift was when i used a diesel additive. But once you figure the cost of the additive, it was a wash with the MPG increase. Also with the additive i would get a CEL on a rare occasion on downhill grades. Dont ask my why but it happened on three separate trips. When I skipped the additive it never happened.
What i personally think killed the mileage was the transmission program and TC. I used to hate driving it at 55mp. It would never goto 5th gear and constantly let the engine rev up and down. I have a 26mile one way commute on 50mph road I go through 5 traffic lights (all in one short section). If i went 62mph it would shift into 5th and lock the TC. That is when i got best fuel economy. The problem is that around 55mph it was always searching for something. It drove me absolutely nuts. On the Freeway it was ok, but passing it would downshift and redline and you wouldn't accelerate. I found you had to ease into the throttle so it would stay in the same gear and it would accelerate just fine. I absolutly hated all of the shifting. I read about the TC changes and chips that fix it, but in the end it just adds more cost.
At 35k miles i started to notice clunking in the front end. with the lift kit, the ball joints go. again you can buy aftermarket arms with replaceable ball joints. I also noticed that I had a CV joint starting to go. I attribute that to off road and the CRD's torque. Also i noticed the rear main seal on the engine started to go, and then later the front started to leak. This was due to the crankcase vent fouled with oil. Too much CC pressure. Once i fixed/cleaned that, the front stopped leaking, but the rear continued. It was a very small leak. About 2 drips per week, but enough indication it was not going to last to 100k or 200k like i planned. Also i noticed around 30k miles that the differential input seal started to develop a leak as i noticed the slight amount of wetness at the housing. On one of my last trips it really started to leak and at that time i noticed the seal on the t-case started to go. This is due to incorrect pinion angles. Once you install the OME lift you are about 2-3deg out of spec for that drive shaft setup. I could not find anyone who could correct this. At 37K miles i noticed that my engine mount on the passenger side was split. I would hear a clunk on acceleration, looked it up and others had the same issue. When i looked at it, it was torn.
So in the end, if you want to keep it running with a lift, expect to correct issues for it was not designed to handle. I used to work for chrysler in college doing hot weather and durability testing. During that time i drove many many jeeps with diesels and they were fantastic. They only thing was that the were all for export - different tuning/calibration. The north america tuning for the CRD was all wrong IMHO. it could have been executed much better, but the emission laws created issues. All of the emissions components were an afterthought on the 05-06 liberty. If you were to drive an export only 2008 to present you would notice a difference in performance and fuel economy.
One thing to mention. I used THULE cross bars with my airland on the factory rails. I noitced that the factory rails started to get stress cracks at the interface between the aluminium tube and the plastic peice which attaches to the roof. I found this was an issue for others, and again you may be able to find an aftermarket one that would work better.
In the end i put a ton of miles on it but figured the cost was going to be too high to keep for a long time. The fuel economy difference between the liberty CRD and a 4 door rubicon is canceled by the difference in price between the two fuels. I now own a 4 door rubicon and get 18-19mpg ave and spend less per month than I did for the liberty. Also my rubicon is stock and has better off road performance. the rubicon also has much more interior space as well. I figure by the time you find a used liberty CRD and try and get it to perform as well as a used stock rubicon you will be almost equal in price. Another consideration is the service costs are less with a gas rubicon than the CRD. CRD uses more oil and a weird grade which is not always available 0-w50. The air filter gets dirty faster due to turbo. More filters to change - fuel filter, turbo solenoid valve filter. Its true that the rubicons 3.8l is sluggish compared to the CRD, but all of the hassle of the CRD was not worth it for me. If you dont need 4 doors, you may want to consider a LJ rubicon. A good used 2006 LJR will not be that far off in price as a 2006 liberty CRD.
My plan for to mount the airland on the rubicon will be to utilize the front runner roof mount system. 3 cross bars and 4 tracks that will go the entire length of the roof. I plan on making a braket for the front cross bars and a strut for the the rear section of the roof to help distribute load to the body.
This is not meant to discourage, but consider the CRD is very niche vehicle that has quirks. For me in the end a stock rubicon fit me better. I dont have to worry about aftermarket parts and what their effect will be on other components or systems will be. Its easier to maintain, and the top comes off! It is all around just much simpler for me.
Attached are pictures with my CRD setup.