Just got back from Expo and another pass on the White Rim Road in Canyonlands with my ZR2. We did parts of the more challenging Hell Roaring Rim Road (HRRR) before doing the White Rim and I got to experiment with the lockers. In one spot there was a large double ledge that could not be taken with much momentum. I purposely approached it without lockers on and got some wheel spin which prevented me from making it up easily. I backed off and locked both front and back and it motored right up.
Approach angles are really great. Departure angles LOOK really tight with the spare underneath and that exhaust sticking out down low, but it was never a problem. I only lightly scraped the hitch once when I wasn't being careful with my speed.
The much discussed shock mounts can be protected with Fab 589 shock mount skids. I put them on just in case but they weren't really needed. I can certainly imagine situations where a boulder field would cause problems, but most of the time there are line options that make it a non issue. Still, it's cheap insurance for those very expensive shocks.
The diesel is great for low-range rock crawling. The torque down low makes crawling really easy. 1st gear isn't quite as low as I would like in some situations, but it has the low-end power to make it work.
Width was a non-issue even though the ZR2 is a bit wider than the normal Colorado/Canyon.
The 31" tires were fine. I would go with 32" tires if I was going to upgrade. Yes, AEV had 33's on their truck but they told me they had some rubbing at full articulation. I liked their snorkel kit:
https://www.aev-conversions.com/aev-releases-colorado-parts-overland-expo/
cbi had a great bumper that's coming soon:
Regarding payload, I wouldn't hesitate to put a FWC Swift in my short bed crew, but it's going to need airbags for sure. I wouldn't want to lower the back end much because it would make departure angles even worse. I spoke with Stan from FWC at Expo and they can't install one in a short bed Colorado/Canyon -- apparently because the fuel tank is in the way of where they need to install the tie down bolts in the front. He claims that it has been done by some customers who came up with their own custom tie down methods like welding stuff to the frame and going with arms (Like Torklift tie downs) outboard of the bed side. If you have aftermarket rock sliders he suggested welding an attachment point on those, but the stock sliders have really thin supports so I wouldn't want to use those unless they were reinforced. In the back you could go with a button on the bumper, but I'd rather figure out a way to attach to the hitch bar. All this sounded like a lot of work to me so I'm probably not going to seriously look at that option for now.
Lastly, I think the ZR2 is a great option for those of us who want to follow our overlanding friends around, but don't really have the desire to build up the truck with lots of parts. It's pretty capable off the shelf.