I've had a Carbon Fiber Columbus for about ten years now and I agree, they aren't for everyone. AutoHome makes you prove that are worthy to get one, I don't think the factory can make very many of them, and very few make it to the states. The previous post is correct, carbon fiber is quite different from fiberglass, but I don't think it is any more difficult to repair, you would be using epoxy resin. The tent is so strong I don't see the need to repair for anything short of a rollover. This tent was a special order from Land Rover Experience. They ordered 100 of them and AutoHome decided to offer them to the public after that.
It really is just a very light strong Columbus, the design is the same. Weight savings is about 20 pounds and to me, it really does make a difference. I can't tell any difference in gas mileage or handling. Years ago I used to have a lift so it was easy to get my old fiberglass Columbus on and off. These days I don't have a garage and to get it on or off I have to ask my wife or neighbor for help. If you take out the mattress before, the shell is quite light, seem like about 70 to 80 lbs so pretty easy to handle. The tent lives outdoors full-time and here in Oregon it really rains a lot and it has held up well. The downsides are the price and the color. Personally, I like the white gelcoat, it reflects heat better and is easier to take care of, darker color gelcoat fades so you have to wax about twice as often. I had a standard Columbus for ten years before and really liked that tent too. The difference isn't that big. I've taken off the labels so it is really stealthy and no one knows it is a roof tent. So, my advice is, if you need a roof tent and use one a lot, then it is worth it.
One thing to take into account is resale. I've had good luck with AutoHome tents. My first tent was a Maggiolina that I bought for $1200 back in the 90's, sold it for more. My first Columbus was about 2000 and bought it for around $1100 and sold it for $1200 years later, the next Columbus was about $1900 and sold it for $1600 to get the Carbon Fiber tent. I think I spent $3300 on it and could probably get $2500 so it will probably cost me less than $10 a month to own it, less opportunity cost.
Before I forget, one thing I have found is that buying a roof tent is not like buying a standard tent. It is more like buying a sleeping bag. Buy a tent that fits your needs and can handle the conditions you plan to go out in. We tend to buy things on the big size and a roof tent that is too big isn't necessarily a good thing. My first roof tent was a large expedition Maggiolina Adventure, a great tent but way too heavy at 170 pounds +. I didn't need or want the room. I bought it because it was only $300 more but a smaller Columbus was so much better for me. I didn't need the capabilities of the Maggiolina. - One caveat, I'm not totally impartial, I worked with the factory in Italy back in the 90's and would import them into the US on a very limited basis. They were a great company to work with back then.