I agree, hit or miss. My dad had a 35c with a super kit, and I have a friend with a super 35 c clip eliminator kit, and both turn 33's with no problems.
On the flip side I've seen others snap shafts and bust up their 35 real bad on the trail.
Highway driving on 33's and smaller unlocked you'll probably be fine. If you lock it you'd better put a super kit in and carry spare shafts just in case. If you know its back their and don't be top harsh on it it'll be good to you.
With my experience I'll be doing a super kit and a Detroit also sleeve/gusset it with 33x12.5 r15's and 4.56's. I drive mine on the highway and pick my lines well, avoid tire hopping, and abuse of the jeep in general so I'm 99.9% sure I'll be ok.
Your options are a d35c, ford8.8, and d44 or d60 if you're effing crazy like that.