So I played a good bit of gen VI on showdown and I really like the feel that I get with this generation. A few things:
1) Team preview still sucks. It might even be necessary, but I still dislike it. I don't hate its existence, I hate its requirement.
2) Aegislash is annoying. It always gets going, but isn't particularly threatening when it is. It made me run more EQ(s).
3) Talonflame is cool. It might be able to break the UU wall, but not by much.
4) Mega Kangaskhan is surprisingly decent. Double Fake Out -> Double Sucker Punch is decent for revenge killing, and then double Frustration hits hard while double Power-up punch / Drain Punch does the utility of your choice.
5) Crits feel so much nicer in general. Game changers, but not as overwhelming.
6) Azumarill is now decent, but not as hype as everyone was expecting(hoping). I find its typing making it laughably easy to get Belly Drums combined with Sitrus Berry, but then it just gets stopped in its tracks.
7) Defog is a welcome change. I run it on my Scizors just to try it out and I like it so far.
8) Mega Lucario is the best mega, but ice punch on my set isn't doing as much as I want it to. Maybe E-speed, SD, or even iron tail.
9) Mega Heracross, Banette, and Aerodactyl all suck **** and should never be used.
10) The previous point SERIOUSLY applies to Aerodactyl.
11) Points 9 and 10 are serious.
12) Metagross sucks now. Explosion nerf and steel losing resistances is too much... if Explosion was back to gen IV and it ran assault vest, maybe... hope for changes in Z(like Hypnosis in platinum).
14) I don't know if this generation is better or if people just aren't using gen V stuff yet. Regardless, Sticky Web is pretty mediocre because you use an ass pokemon to get it up and don't do much with it(excluding specific pokemon).
15) There is no point 13.