"Grave Secrets" is one of only two Kathy Reichs books I've read (I picked it up fairly randomly in an airport a couple of years ago) and I didn't mind it. Pretty much forgettable and requiring no actual thought, so yeah, a good beach read (if you like lying around on beaches, which I don't). I don't read a lot of contemporary crime/thriller stuff, though, so I have very little to compare it with. And I've had no desire to pick up another Kathy Reichs since, so that probably tells you something :)
(I do like what I've seen of Bones though, mainly because I'm rather fond of Brennan in that, and her relationship with Booth is quite fun).