Levinson 29 vs 27.5 vs 23.5

How would you compare the sound of these 3 amps? Beyond the differences in power, are they basically the same or do they have different sonic signatures? For example is the 29 warmer, but the 23.5 more dynamic? I have amphion argon2 speakers (87db sensitivity) and am looking for the best fit of the three. I heard the ML 29 years ago and was extremely impressed. I'm concerned that the 29 might be underpowered at 50W, but if I go with the 27.5 or 23.5, will they have the same lush sound of the 29?

I apreciate your opinions. Thnx