Well, I've done this for mouthpieces, so let's do this for barrels (at SteveSklar's request).
My experience with barrels is to use them for correcting intonation difficulties when fooling around with friends' R13 and 10, respectively, and only using stock barrels. The majority of the clarinets I've owned have been in the student to intermediate range and don't have extra barrels and/or sound juuuust fine with my mouthpiece.
There are a lot of 3rd party barrels out there. Do they really make that significant a difference?
My experience with barrels is to use them for correcting intonation difficulties when fooling around with friends' R13 and 10, respectively, and only using stock barrels. The majority of the clarinets I've owned have been in the student to intermediate range and don't have extra barrels and/or sound juuuust fine with my mouthpiece.
There are a lot of 3rd party barrels out there. Do they really make that significant a difference?