Nakamichi vs Mcintosh?

Well, I really hate arbitrary scales like that, but, to answer in those terms McIntosh amps are among the absolute best available.  If 10 is an ideal of perfection that cannot be attained, 1 is unusable and 5 is average, McIntosh amps are probably around 9.5 or so.  When Nakamichi made their amps in the USA (1995 to 2001 models) they were very good, probably around 7.5 to 8 on the imaginary scale.  Earlier Nakamichi gear built in Japan (mid 1980's to early 1990's vintage) were probably better.  The more recent post-bankruptcy Nak amps using mainly parts out of the far east factories are really not much better than any others coming from those factories, and would be down around 6.

Nakamichi head units are among the best in the world, although their build quality can be really dicey.  Out of the box failures are not uncommon, so always buy with a warranty from an authorized dealer.  McIntosh heads are built by Clarion in Taiwan under contract and are genuine high end units but have a shrill sound quality (to me) and are not the most flexible things on the market.  Eclipse by Fujitsu Ten is in the same quality range and tends to be more reliable and easier to use than either.