I've tried and... I just can't. I simply can not get into this game. Despite all it's flaws, I really, really enjoyed BF3. 350~ hours logged public. 50-100 clan games on top of that. You get the picture. Part of the problem might be that I was so heavily invested in BF3. Who knows. So far I've managed to articulate a few things that I think drag the experience down in BF4.
Gunplay and movement
BF4 seems far more lethal than BF3. You and your enemies die a lot faster. I've checked the damage values and they appear to be roughly the same, so it probably has to do with the netcode or the increased controllability of weapons. Either way, this makes fight a lot shorter and makes movement far more costly. If someone got the drop on you while you were pushing in BF3, it didn't mean the fight was decided. You could jump into cover or simply out-aim them if your reflexes were good enough. This isn't realistic by any means, but it was fun. It's hard to describe, but BF3 infantry combat was just more flexible and enjoyable.
Maps
My beef is primarily with Siege of Shanghai and Operation Dawnbreaker and those kind of maps. Running across 6-lane motorways without much cover isn't fun. Neither is the "all or nothing" approach to verticality. You're either at street level or way above the ground. This creates awkward, angled sightlines between ground troops and rooftop huggers (Zavod 312-something comes to mind). Compare this to maps like Kharg Island or Gulf of Oman that featured 1-3 story buildings that had easily accesible staircases. This kind of verticality felt more tied into the actual battlefield and storming those buildings was actually one of my favourite activities. They were also very destructible and not giant, invulnerable monoliths.
Post-processing and art
The maps look absolutely incredible, but are very often very contrasty and blasted with a bunch of effects (blinding lights, sun of doom etc), which makes them hard to read a lot of the times. This also creates a very big difference between an un-spotted enemy which can easily blend into the very darkened foliage of a stormy Paracel Storm and a spotted one, which shines up like a christmas tree. This means that, a lot of the time, you will be firing at orange doritos instead of actually aquiring targets. This was not at all as bad in BF3.
I do like a lot of the tweaks and changed features, but as long as the infantry experience isn't fun, they are of little importance (to me, this is all subjective).