Things that have improved under Unai so far:
1) we have the defensive midfielder we have needed for so long and that Wenger consistently refused to buy often then forcing players into the role who didn't really fit i.e. Arteta, Xhaka
2) he's getting rid of Ramsey
3) it was mentioned on Sky the other day and even though it hadn't occurred to me I think they were right, we seem fitter
4) you can see young players getting better i.e. Iwobi, Bellerin, who seemed to be stagnating under Wenger
5) he's getting rid of Ramsey
6) Poorly performing players are being hooked early on i.e. Ramsey, Ozil
7) he makes more daring substitutions and his substitutions are having an impact, much more so than under Wenger
8) he's getting rid of Ramsey
Things that look worse under Unai so far:
1) we're more open at the back although I would argue that our defending when we are under pressure seems better; possibly because of Torreira, possibly because the players are in better positions to recover
2) we still don't look comfortable playing out from the back and 1) is often because of mistakes made when we're doing it
3) it isn't yet absolutely certain that he's getting rid of Ramsey