One thing I know for sure that if you don't plan to pick up one of your Macs locally, you'll have to allocate even more for shipping of monoblocks that weigh same or heavier than whole MC352.
As many posts you find about overpowering speakers all of them in one voice will spell that it's better than underpowering, but in your particular case with domination of slow and mild music you don't have to go crazy and can easily go to less pricey unit.
To say that it's an upgrade to your current Krell is more of your personal preference. I found Krell's been doing a great job for jazz. Many would say that Mac uses pre-historic autoformer technology that can be jeopardised by modern direct coupled circuits, but on my experience they show opposite. They sound great with any speaker you choose with any style of music. No DC to speaker issues either.
As far as input design goes, it's upto date in both of these Macs. Double balanced differencial vs. Fully balanced differencial have little to no differences performancewise and you can easily consider them both as balanced amplifiers.
As many posts you find about overpowering speakers all of them in one voice will spell that it's better than underpowering, but in your particular case with domination of slow and mild music you don't have to go crazy and can easily go to less pricey unit.
To say that it's an upgrade to your current Krell is more of your personal preference. I found Krell's been doing a great job for jazz. Many would say that Mac uses pre-historic autoformer technology that can be jeopardised by modern direct coupled circuits, but on my experience they show opposite. They sound great with any speaker you choose with any style of music. No DC to speaker issues either.
As far as input design goes, it's upto date in both of these Macs. Double balanced differencial vs. Fully balanced differencial have little to no differences performancewise and you can easily consider them both as balanced amplifiers.