As a fellow HA-160D + LCD2.2 owner. I wonder the exact same thing as you. Since I haven't been able to listen to my LCD2 on any of the popular amps with high current output, I haven't been able to compare either. I can only read the good things people say. I am pretty satisfied with HA-160D, as even loud listening for me works quite well. I am however curious how these other amps compare. Ignorance is probably bliss in this case, but if anyone out there has any direct comparisons of amps like the Mjolnir with HA-160 I would really like to hear about them.
If you like the 160D + LCD2 (which I never did), if you do upgrade in the future I think the Soloist may be something you might like, major improvement over the HA-160 but still far cry from being in my personal top 10 amp list for the LCD2's. YMMV.