They're fun. They hold their value pretty well, so typically economically painless to dabble in. In my opinion, if they are in proper working order they will smoke anything in the Reference line in every way.
If you google up "MBS Audiolab Cornwall Test" you will find a rather thorough review, with measurements.
edit: Hey, I just noticed you recently bought some Lores and are getting into speaker building. If you like your Lores, you would probably really like Cornwalls. And they're fun to project with, from the network/driver upgrades to the cabs. Cab work in particular, since you're getting into that sort of thing, can pay real dividends. Beat up corns go for a few hundred bucks, but cosmetically nice ones can fetch quite a bit more.