Identifying a good/bad/mid draft class

I have my draft classes set to default, as I figure randomness is good way to keep the player pool generally consistent. But when looking at a given draft class, what are you looking for to determine if it's a strong or weak class? This matters to me for deciding if I'd want to obtain (or shed) extra picks in a given draft.

Similarly, how are you identifying the strength of a given draft class? I can do a general eye test and see "lots of CBs in the mock draft" or "not many IOLs in the top 50." But that doesn't tell me if those players are good or bad, just a concentration of positional groups.

I'm usually looking for the # of A-rated AWR as a guide but that's a) probably not sufficient and b) something that isn't revealed until close to the draft.