Hey,
I have both books, and I like them both a lot. The Netter's ortho (green cover hardback) serves more of a similar role of a Miller's, with concise info arranged by topic. It is good for a general overview and has some good illustrations to supplement text. The "concise anatomy" (paperback) is more focused on the pictures/anatomy with text as a supplement. It is good for pimping qs esp with surgical approaches, etc.
So I would say base your decision on:
1) whether you learn better by text (hardback) or pictures (paperback)
2) how much you need a primer on anatomy, surg approaches
3) what other books you have (Moore's, a general Netter' anat, Miller's, etc)
I myself would lean towards the hardback, I think it has a bit more bang for your buck; I don't think you'd go wrong with either one (or both...) though!
-OR