Castlevania Anniversary Collection is excellent. This is the era of the series I feel was possibly the strongest and most memorable overall. I would have liked them to sneak in Dracula X SNES and possibly Rondo of Blood; that would have made it phenomenal. But it's still great. Kid Dracula I could take or leave, but I appreciate the effort was made to bring it over for those interested. Bloodlines being on this was the key for me, as it's the only other game on this collection I don't own, and I've only gotten to play it a handful of times over a decade ago.
That being said, there are some issues...
-I've had an instance of input lag and a brief touch of sound errors on Super Castlevania IV. The flipping green platforms in Stage 4 don't allow you to jump off them in time like on the SNES unless you double-tap the jump button. (I'm playing the PC version on a lesser-powered PC, so maybe that's related?) The sound bugged out for a second on Stage 3's latter portions.
-Castlevania 1 froze on me on the screen with the harpies just before the staircase that leads to Dracula.
-There is a high-pitched sound bug starting in Stage 2 of Castlevania 1.
All of these problems can be ignored or counteracted through different methods, but hopefully there will be a patch that will fix these as time goes on. There reportedly will be a patch with the Japanese editions of all the games except Simon's Quest. But you know, rather than a second collection, I'd almost like a way to add DLC games to this one--stuff like Dracula X, Rondo, X68000 Chronicles--at least until we get to Symphony of the Night, should there be a Metroidvania collection.