So many thoughts, I should read through and keep a log for the later surveys (does anyone else have ten things to report and forgets 8 of them a week later?).
Fighter looks cool, but the Rogue has started to look dull and static in comparison. I think that's because the Fighting Styles are adopted themes that would otherwise suit anyone. I think they might have to think carefully about who gets what here.
Clerics are pretty awesome, though I note that they don't seem to get better at spells/attacks in those 5 levels. I like different priests getting different armour and weapons, but hm, they still get the same hit dice, which is a major indication of combat ability.
Rogues, as noted, seem a bit dull. Great at skills. Sneak Attack *is* too high because there will be a million ways to gain advantage as the game progresses (the Fighter knockdown combo as noted is one). It's also putting all your eggs in one basket - it would be nice to trade off some damage for some other effect (but then you're treading on combat superiority so hmm I am torn).
Wizards are fine. That is all.
HP seem low - Wizards go back to one-hit kills. There has to be a better boost at 1st level for the PCs. Haven't really got into the other changes yet!