(Note: I'll refrain from comparing Crystal to the 90s anime and the manga; the former because it has a completely different format, and the latter because I think an adaptation should be able to stand on its own merits.)
PROS:
The music is great. I've heard people complain that it's "not memorable", but I personally found most of the tracks fantastic. Really helped set the mood.
Gorgeous animation, when the show actually bothers to try. The BDs are a boon too, of course, and they fix much of the oft-reviled lineart.
Good voice acting. Kotono especially, but the others play their parts very well. Beryl's VA is a standout.
Many sweet and/or touching moments - Chibiusa's backstory, Mako's intro episode, and pretty much everything about Pluto, for example.
CONS:
Rather silly plot developments. The Holy Sword makes no sense, as discussed in another review below. The Sailor V game hands out magical items and is conveniently placed right on top of a secret base. Usagi is genuinely worried that an eight-year-old will steal her boyfriend. The show crams in no less than eight instances of brainwashing and three Silver Crystals. And so on.
The Inner Senshi are laughably ineffective, especially in the Black Moon arc, and have little personality beyond their focus episodes. Other supporting characters are borderline pointless (looking at you, Asanuma).
Villains lack motivation and are defeated anticlimactically.
A lot of padding, usually in the form of drawn-out conversations, and copious MotW action in the early parts of both arcs. Sitting through five consecutive transformation sequences doesn't help much.
Bad animation - individual frames don't bother me too much, but the show is constantly hampered by jerky movement, bizarrely Off Model episodes, and poor cinematography.
The Senshi/Shitennou "subplot" was, frankly, a horrendous affront to all eight characters involved. I'm not opposed to the ship on principle, but a 10-second montage does not qualify as believable romance.
Despite the various issues above, I do find the show enjoyable, and I hope it eventually covers the rest of the arcs (with a bigger budget, heh). If you like the manga, Crystal is worth a shot - if not, it probably isn't going to improve your opinion.
Disappointing
(Note: I'll refrain from comparing Crystal to the 90s anime and the manga; the former because it has a completely different format, and the latter because I think an adaptation should be able to stand on its own merits.)
PROS:
CONS:
Despite the various issues above, I do find the show enjoyable, and I hope it eventually covers the rest of the arcs (with a bigger budget, heh). If you like the manga, Crystal is worth a shot - if not, it probably isn't going to improve your opinion.