i watched it all in one day (yesterday). i overall really liked it. my biggest complaint was that because the episodes were each a good bit longer than the original three seasons (>30 minutes compared to - what? - 22ish?), some parts seemed to drag.
i can see where the concept would be a little weird/offputing - focusing on one character in each episode, not necessarily having a set order - but i liked it.
normally, tobias is my favorite main character followed by lucille, but on the first watch, i enjoyed the GOB and buster episodes the best.
lots of little funny moments, and i'm sure i'll pick up on more stuff and like the episodes even more upon rewatching. it's the kind of show that improves upon rewatching, because there are so many more things you notice.
FWIW, most of my friends are AD fans, and they all seem to like season 4. maybe not as much as the original seasons, but they're still liking it so far.