I haven't gone back to BF4, just have played BF1 less. I loved BF1 for the first 100 hours or so I've put into the game, but I just can't stand having to deal with things like these anymore:
Vehicles can be out of control if you're in a team of people who don't really want to work together to take them down. And I can sorta understand why they don't want to bother. They are high risk with low reward. Destroying 1 tank with 6 people in it is a jackpot, but it doesn't really happen often and most of the time you may not be the one that get the final kill on the tank, so all your hardwork is rewarded with measly score points that can be gathered elsewhere.
Related to the point above, especially pilots that know what they are doing. They can be a hell to deal with. I think it's just too much power for a single player to be honest.
I've grown to hate how uber powerful the automatico is. The thing with it is that you don't have to ads to do well with it, just hipfire all day everyday. Only the 10A hunter can win against it in close range, assuming both players are similarly skilled with aiming. I can use the gun too, in fact I already have like 700 kills with it, but I'm the type of player that likes to rotate my gun usage just for variety.
Grenade spam is almost reminiscent of CoD 4: grenade warfare. Especially gas grenade. The assault class is massively advantaged since they don't really have to ads.
I seem to get killed by snipers a hell lot more in this game. You can't be in an open area for more than 3 seconds before someone pop your head off, or if you're unlucky, get sweet spotted.
I dunno, looking back I still think Bad Company 2 is the most fun Battlefield I've ever played. May not be the most battlefield-like if it makes sense, but certainly fun and not all that frustrating.