Likes: The options to turn things on/off. The extra HFS is also a lot of FUN. All the FPS fixes and generic materials - as much as having Forgotten Beast pants is an amazing thing, the FPS bump is worth it for me. I kinda like the research aspect, although in practice I find it a bit more complicated and unwieldy than it could be. I like the idea, but I get annoyed when I use it, mostly because of all the reagents.
Loves: The new workshops, especially the Blast Furnace and others related to the metal industry.
Dislikes: The new pets (I like cats and chickens and can't seem to get them back through the options menu), the idea that Drow are a "good" race, and all the high magic elements, although that's just my taste. The disease stuff is pretty broken I think, although it can be highly amusing (puke everywhere). I've never played the other races because they don't interest me, so I can't say much about that. Also, warlocks. I just turn them off.
Overall: At this point, I only play with either Meph's Accelerated DF mod when I want a more vanilla DF that actually runs fast, or Meph's Masterwork Mod when I want things to turn into a crazy, dwarf-blood soaked shitshow quickly. It's really hard to go back to Vanilla DF now. So, thanks Meph! Keep up the good work. I probably won't play the new version until you mod the hell out of it.
Also, I liked Legionaries' suggestion of a few default configurations. There is a LOT going on in the mod after all.