The only dumb thing I've seen so far with the new system is gaining LP when you're trying to jump up a tier (say, Silver --> Gold). I'm currently on 97 LP Silver I, and the last 4 games have each given me 2 (two) LP. So I'm basically going to have to win 5 in a row, AND THEN win a best of 3/5 series. I'm sure I can do it, but jesus, one loss thrown in there \is going to sink 4-5 games worth of progress, which seems ridiculous.
I get that once you're Gold it's permanent, so it has to be difficult, but having a win for a measly 2 LP just seems silly. I haven't lost one yet, will be interesting to see how much I lose at this point.
EDIT: Even nicer, I just got 1 (one) LP for a win. Up to 98, joy oh joy.