The last time I heard the T5 was quite a while ago at a show. They are easy to drive, in a lot of cases 60 watts may be all you need. They are 16 ohms so making power with a tube amp is easy with them.
The thing is, John has been updating the T-3 and T-1s with field coil drivers and new crossovers, but I have not seen that happening in the T-5. Prior to that though, the big differences between the T-1/T-3 and the T-5 were these: the bass was smoother response in the T-5 owing to the dual woofer, but did not go as low (31 Hz) and it is slightly less efficient.
The T-1 and T-3 both got dual woofers at a later time.
Now as to Duke: in hearing his speakers recently, I am not sure that there is any particular advantage to the T-5, as Duke's speakers are similar drive-ability and bandwidth. His designs perform well out of their price points as far as bandwidth and resolution, so I think it is sound advice that Tvad has been offering. OTOH you might contact John and see if he has any field coil offerings for the T-5, if so I would keep them under consideration as the field coil drivers are something special in the resolution department.
The thing is, John has been updating the T-3 and T-1s with field coil drivers and new crossovers, but I have not seen that happening in the T-5. Prior to that though, the big differences between the T-1/T-3 and the T-5 were these: the bass was smoother response in the T-5 owing to the dual woofer, but did not go as low (31 Hz) and it is slightly less efficient.
The T-1 and T-3 both got dual woofers at a later time.
Now as to Duke: in hearing his speakers recently, I am not sure that there is any particular advantage to the T-5, as Duke's speakers are similar drive-ability and bandwidth. His designs perform well out of their price points as far as bandwidth and resolution, so I think it is sound advice that Tvad has been offering. OTOH you might contact John and see if he has any field coil offerings for the T-5, if so I would keep them under consideration as the field coil drivers are something special in the resolution department.