I think that alot of the the feeling different (at least for more, not saying for others) is mental a thing. I use to say that I could feel the difference until my current partner and I had an accident changing positions. He was the first to notice that it felt different.
In my case I think the very fact that I know the man is wearing a condom causes the sex to feel different.
Now there is a type that he and I used that we got as a free sample that honestly felt like he was wearing nothing. He even claimed that it felt alot like going bareback. I'll have to ask him which brand it was.