Does anyone have experience of the Wessex Tubas FB-124 flugabone vs the Dynasty M566 marching trombone? I've got a very good example of the latter (no dents or dings, seems to have lived undisturbed in an attic for a decade before I bought it) but to my mind it's very "stuffy" to play and the sound is very "thin". (My other instruments are JP Sterling 373 Baritone, B&H Sovereign 967 Euphonium and B&H Sovereign tenor trombone, all of which play much more freely and sonorously for me). Is the FB-124 better than the M566 or should I continue my quest for an Olds O21, King 1130, Blessing M200 or Kanstul 955?