One thing the new client is good for:
It has weeded out a lot of players with crappy pings. If you were lagging before, you're probably lagging way worse on the new client, or arriving to the Champ select screen very late.
Seriously though. Every game someone highlights their ping in chat, and some of them are crazy! Can you see the screen at 1400ms? Maybe I'm misunderstanding the terms ping and lag and latency, but that can't be good. I'm guessing you probably shouldn't be playing if your ping is that high.
Since the new client I have seen less of it, but not because it's faster, LOL. Just sayin'. The only way around the new client is to get a new, decent PC or a better connection, or both. Or quit. With the AFK issues some of you have, it should be the latter. It's frustrating for everyone. So why don't you just sit out the next few hundred games, until you can achieve better PC speed.