I built up a set of wide 29er carbon light bicycle rimes, straight gauge spoke to CK hubs and have been loving them for over a year now.
I am over 260 right now and was quite worried going over to carbon rims….but to my surprise they have been great and I have hit them very hard.
As Cam said one of the advantages is running lower pressure. I was out riding at one of my local spots and thinking how amazing the grip was while I was climbing to the top….I look down and I see the rear tire just envelop a little rock….a quick check and I see I am running 19psi in the rear and 17 in the front…whoops. I didn't put any air in the tires till I got home…had no issues on the ride back down the mountain.
Running ghetto tubeless I have not burped once in the year I have been running them. I have ripped a sidewall and was surprised how easy it was to mount a new tire (with better casing), I just used my floor pump to pump it back up. Easy. The rims are hookless too.
People like to shit on what they don't know or something that is different. I have ridden both and I can't see myself going back to little ID rims anytime soon.
With all that said, I would love to try putting some 27.5+ wheels in my Prime for shits and giggles…see if bigger is better…lol.