Eidelweiss. http://edelweiss.abovethetreeline.com/, my username there is donealrice (no idea how to link directly to profile).
No, I haven't started doing ARC reviews. But, their book catalog and features look quite promising for someone like me who seldom reads (or publicly posts about) the indie books not added to Eidelweiss.
Unlike some sites trying (*glares* at LibraryThing), I can already figure out how to mark a book as currently reading and want-to-read. And how to write a review.
Bitching site for finding new releases even if you don't want to join; can filter all kinds of things when browsing.