Which mono power amp would you choose and why?

This is not an answer to your question, but it may be helpful. I also have the LA4 and AHB2. I love the combo and will have this long term with my KEF LS50 Meta.

I will get a second LA4 for a system with potentially power-hungry speakers. I heard these speakers with the very powerful Hegel 30 mono, and it was a really fun listen. Not the cleanest sound on top but really fun.

I read about the new Rotel Michi M8 on A’gon, which is even more powerful and cheaper, so I went for a listen. The dealer only had the top end integrated but I was able to hear the Michi sound and it was pretty good, very quiet. It was not as clear sounding as my Class A or AHB2 amps, but it was rather good.

Rotel Michi M8 monoblock power amplifier | Stereophile.com

I am debating whether to go for massive power with the M8 (very useful for my potential speakers) or ultimate refinement with high power Class A (Krell or CODA).

Michi M8 Mono Power Amplifier; Black Pair (Open Box) - The Music Room (tmraudio.com)

@alucard19 There is also a S5 stereo Mitchi amp that is in your power spec range available on USAudiomart. Though the price is not that great.

Michi (Rotel) S5 Amp Like New Powerhouse! For Sale - US Audio Mart

If you get a Michi I would be interested to hear your opinion. I have a tough time dismissing this amp as a contender.

@jaymark Is your CODA #16 as powerful sounding as the other amps in your possession? I am also thinking like the OP to buy something with massive power over refinement. The CODA #16 is my idea of a refined amp the Michi that I referenced above should be an exciting amp but not as clean on top. I have heard both lines so that is where this opinion is based on.

I had a very fun 1+ hour demo with KEF Blade 1 and Hegel H30 monos in a big room. It also was not as clean sounding as the CODA #16 but a super fun listen. The H30 and Michi M8 are identical power wise. The Michi X5 I heard sounded a lot like Hegel, Class AB sound. Slightly grainy, with the Michi maybe smoother.

I just got off the phone with a local audio store and they said they will be getting the S5 or M8 in the shop in 2023. So, I am going to wait to hear these before I buy anything else. Until then a Peachtree GAN1 amp is coming in next week to hold me over.