At Spirit we play on Kanstul BBb 5/4 Contras (we have 4 convertibles and 6 fixed). I love playing on the convertibles more, not sure why, but they sound better, and it seems like i can play louder. They're also slightly heavier, if that has anything to do with it. In 2000 we played on yamahas and i hated them! It was awkward to hold and with the straight up valves it was not pleasnt. But i love our Kanstul contras, Although a few things to be advised about. The C's are badly out of tune not matter how far you pull the "tune any note" slide out. There are a few other notes that are iffy, but no horn is perfect.
Peewee