mono versus stereo ampflication

Yes, I think "it depends." Key questions would be how much power do you need, and how much power can the speakers handle? Questions that would relate to how much power you need would be the size of the room, the distance to your listening position, and what kind of music you listen to. For instance, audiophile caliber recordings of symphonic music with loud crescendos or heavy bass drum whacks would require much more power than jazz or chamber music.

Also, do you have the physical room for two large monoblocks?

My instinct, given your price range, would be to go with monoblocks if you have the room for them, but specific recommendations would be dependent on your power requirements.

Regards,
-- Al

I think that there are far too many variables involved to be able to generalize as to whether monoblocks or single-chassis designs will be better.

Gammajo, it sounds like you need lots of power. What is the max power rating of your speakers, and would you want to future proof your selection by making it powerful enough for possible speaker upgrades in the future that might be able to handle more power?

I have no particular experience with amplifiers in your price and power range, but based on what I've read I'd certainly look at the offerings from Pass Labs, Plinius, and possibly Ayre if their lower priced models provide enough power.

Regards,
-- Al

My feeling is that neither the 60W amp nor the 150W integrated are powerful enough, considering the 500W capability of your speakers, your very large room dimensions, and your interest in music that has wide dynamic range.

If I were you I would try to audition one of the higher powered X.5 (class A/B) amps, as your target selection, and compare its sound with the XA200.5 (pure class A), which I suspect is well out of your price range. Assess how much difference, if any, you can perceive between the sliding class A/B design and the pure class A. I suspect it may be small enough that you will feel comfortable choosing one of the X.5 amps, which provide more watts/dollar, as well as functioning less like space heaters.

To answer your specific question, no I don't think that a 200W pure class A amp is necessarily better sounding than a similarly designed 60W pure class A amp, other than, of course, on high volume peaks that approach or exceed the power rating of the smaller amp.

Regards,
-- Al