How big of a difference do amps make?

Case in point, in 2002 I purchased both a Krell KCT preamp and 300cx amp from San Francisco Stereo to power my Thiel CS6s. After half a day of listening I decided that perhaps the more powerful 400cx might be a better match, so I swapped out the 300cx for the 400cx and immediately, I heard more detail, deeper and more highly controlled bass, and deeper soundstage (yes, the 700cx was way out of my budget then). My point here is that even within model lines, and given all else equivalent from a design and execution standpoint, the power supply itself and the current served up to the speakers can make a huge, audible difference.

point could be taken that even amp of less quality with sufficient power may sound better than great one with lack of power.

*I am sure others may have traveled a similar path. So i am looking to hear their experience going from ss to tubes.*

I, & I'm probably others, could go on for hours about going from ss to tubes, & back again. The real issue is: What kind of SPEAKERS do you have? Do they need lots of SS power? Or are they designed to work well with lower powered tube amps? (Like Merlin's).

Merlin's like tube amps--any Merlin owner will tell you that. So still debating SS vs. tubes--what's the point? (Unless you sell the Merlin's & get some power hungry speakers that need big SS amps).

BTW, as far as amps--there are people that design their whole systems around their tube amps--even esoteric expensive amps like Cary 805's say.....(I always wanted to own those).....

That's exactly the correct way to go. You got it!

I was an amplifier nihilist until I went from SS to tubes after I bought my Zu Definitions. Then I went from an EAR 859 to a Yamamoto A-08 to a Deja Vu Audio 2a3 to an Ancient Audio 300b SET amp. Finally, I went from Shuguang Black Treasures to Sophia Royal Princes to Takatsuki 300b. Each change made a difference - some more than others, of course.