I swore I would never own tubes because of the "hassle and expense." Well, I graduated from Adcom GFA555 II's to a Conrad Johnson MF2550 SE, which sounded great (along with my CJ ET5 preamp). Then I took a chance on a used pair of CJ monoblocks and they just sound better. Somewhere between nominally better and noticeably better. More fluid, and more musical, although the CJ Solid state amp sounded pretty good in its own right, and had marginally better damping for the bass. I kept the solid state for my b system, but for the a system, it's CJ tube monoblocks and the now discontinued ET5 preamp. I have toasted a couple of KT120 tubes, but they are only $50 each from upscale, and I have put in a nice Telefunken 6922 in the ET5 from Brent Jessie in Illinois. They are all approaching a year old and they still sound great and I play music 2 hours a night about 3 nights per week. So, I am really no longer concerned about the cost of tube replacement, but I do stock several pairs of KT120's and some 6922 tubes.
Advice/lessons learned? If you want great sound you have to have a great source. So, I needed to upgrade my Rega Rp6 with MM Exact 2 cartridge to the RP10 with the Apheta II mc cartridge to bring that out.
Now, I am really pleased with the sound; symphony, Peter Gabriel, Eric Clapton Live, Mozart Piano Concerto's-- all good. If I was to go back to solid state, I would buy Pass Labs gear-- a combination of used on audiogon and new from Mark at Reno HiFi.
I am not related to any of these vendors; they are just folks who have really treated me well over time.
Cheers