Looks like the question is: How much maintenance are you willing to do for great sound? We know the requirements of tube amps, i.e., tubes wear out and need replacing. Is great sound worth swapping out tweeters every year or so? I still remember my audition of SC-IVa's many years ago as one of the most impressive moments of my listening journey. Everything was simply "Right" (Listening to Sade's "Stronger Than Pride").