Sound quality of Rhino Records remasters?

I haven't compared them to the originals but I've always thought they were pretty darn good.

It really depends upon when the title was released. Rhino has alot of product out there. You'll see titles that were released ten or more years ago. You'll also see stuff which is only a year or two old. Check the copyright date on the disc case. Of course, the more recent stuff sounds better than the older stuff.
By the way, the Randy Newman reissues sound way, way better than the original Warner Bros. cd's. The new "Sail Away" sounds great.

A safe buy if you want the music. Not always up to the standards set by the esoteric audiophile labels, but generally good enough. I have never been disappointed in the sound quality of a Rhino compilation.

In general, Rhino is not breaking its back to produce the best sound possible. That doesn't mean they sound lousy, but on average they're probably not much better than the major labels.