How big of a difference do amps make?

Contrary to Schubert, I drive my Aerial 10T with Sunfire SRA(bought NOS $450). Feels like I need a-bit more power of let's say Sunfire 300(used $700) and I'm sure that it will sound waywayway better than $200Kef with Halcro or Mark Levinson monos. At the same time I don't think that mine do well with 30wpc OTL tube amps or vintage Fisher receiver due to lack of power.

Without sufficient power to the specified load of the speaker neither price or sonic performance copmarison relevant.

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

Tubes, semiconductors or IC It's all matter of design, but you can't wear size 12 shoes when your feet have size 8.