I can understand someone saying I love both games but I enjoy the "atmosphere and exploration in FO3 more." I understand it because those are things FO4 can work on. When someone says New Vegas is a step back its like they don't care about any of the many improvements of New Vegas. hardcoe Mode, Damage Threshold, Reputation System, Traits, Iron sites a better working economy, return of original style Power Amrour, Better dialogue, better Followers, Follower quests.
A few things:
1) I didn't care for hardcoe Mode, wasn't challenging, just a nuisance
2) Damage Threshold was good but wasn't a big improvement to me
3) The Reputation System could have been better, although it is a little better from F3's 'kill somebody, come back 24 hours later and they like you again' thing
4) Traits were not well done or very effective
5) Iron sights was better (I admit it)
6) F3 was in absolute chaos, do you really think they'd have a [censored] economy?
7) Yes it did, and was better with Power Armor, but that was a small thing
8) The dialogue written below the person didn't even match what they were saying 1/5 of the time (no it was worse in Vegas)
9) The followers and quests were somewhat better (If the game didn't have all the followers NCR or neutral then I'd say the were better)
Exploration is a big part for me too.