Played for three hours, got three unlocks: Jarate, Huntsman and the Ambassador. I guess I was lucky. Many people aren't so lucky though, there are many reports of players unlocking items they already had. Like having three Sandmans or something. Or people play for 12 hours and don't get a single unlock. I guess you can play for weeks or even months and be so unlucky that you don't get anything. These unlocks don't require effort at all, they just require luck. You can sit in spawn and go AFK for 8 hours and you might get a few unlocks... or not. And if you do, you might get the unlocks of a class you don't even play. At least with the old system you could choose which class you wanted to unlock weapons for.
I like the unlocks and new maps (Pipeline is great), but the unlock system is epic fail.
Oh, and the scoreboard icons suck. Overall, an update that is both really bad and good.