Psvane "UK Design" 300B is way better than any other Psvane 300b tube and are $350 a pair!I have not tried much in the way of rolling, but had the globes and another set I don't recall at the moment, but currently using psvane 300b's. It sounds great as is but am all for rolling something else to try. Although $ is a consideration, especially after the recent purchases.
Tube recti is consideration, however I have been considering updating the clocks and getting the 512 engine (not r2r), but again $ is a factor and was curious as to some tubes to try that are reasonable $