From all I have read from FairIsaac posts, the major rebucketing (transfer to different scoring algorighms) occurs as a result of: short vs long established credit history, absence or presence of major (60+ derogs), absence or presence of BK (a big bucket), absence or presence of a PR or CA. More minor buckets that all seem to rail the most about, but appear much less significant, are shifts of %util.
If you were about to lend $10,000 to someone, how you want to evaluate them? I think I would want to know which bucket they are in....
I think FICO does a pretty good job of discrimation.