Haven't had enough time with the 90s to rate them fairly. Of the others, I like the 800s over the 60s for comfort and soundstage and otherwise think they're in the same league. Wouldn't even consider the 6X0s again now for anything other than budgetary reasons.
As far as the 800's character -- one man's sterile is another man's incisive. Good Grados are more fun, but they don't match the out-of-head experience you can enjoy with the big Senns.