Over the last 30 years: RV#1 was a 23' class C, used for 13 years. RV#2 was a 27' class C, used for 15 years. RV#3 is a 31' class A with 2 slides. Will never go back; too many positives (IMO). Huge picture window view out the front, both while camped and while driving. Seated up high for much better visibility. Cab chairs ARE part of the living space when camped. Significantly more room, more water capacity, more grey capacity, more black capacity, more storage capacity, more weight capacity, more towing capacity...no difference in gas mileage.
As for safety, that has already been discussed, and it really depends on the type of accident. While it is a bit harder to find service centers for an A compared to a C, don't assume that any Ford dealer will work on a class C; they must still have the room to get it into their service bays. And for the DIY mechanic, in my experience, it is 10X easier to work on my A than on my C(s).