Pulled the trigger on a Moon 861! Hope it pairs well on my Focals

Yes, they do have those tweeters. I also have the Macintosh C12000 preamp so I'm hoping it will soften the highs with its tubes 

I think you bought a great amplifier. I’ve had a chance to hear the 761 and 861 and owned sim  products in the past. I suspect you will find you will have enough power for any speakers, and that the sim audio will not color the music in any way, instead any coloration will come from the preamp and speakers. Congratulations

The MacIntosh preamp may have the balancing effect you are hoping for. Tell us what happens.

Don't forget that a new solid state amp typically starts out very trebly and then softens over the first 100 to 200 hours. 

I know this, but I just can't help but draw conclusions when I put a new amp in my system, even after knowing this for decades. I get all upset... then it settles down. This happened to me recently... and it settled down so much, it was as if it was a completely different amp.  

I think the Persona with Beryllium tweeters are bright in general.  I think the Moon high end amps are awesome.  

I hope your purchase meets your expectations and you are pleased with the pairing.  I'm interested in your thoughts after the amp is run in.  Good luck and cheers!