By way of owning a decent amp(your case the PL Dialogue) for an extended period of time suggests the PL is competent at what a tube amp is supposed to do.
Tube amps aren’t’ doing anything different in those 20 years. It’s not an absolute must, buy you’ll just have to open the wallet wider depending on what you want.
There’s another level of WOW-possibly limited only by ca$h spent.
13 year PL user.