: So far i have'nt been able to match with a hand block 80 grit what i can do
: with a DA sander 80 grit...i am sure it is simply more effort needed but
: it's not worth it.

: I'm still trying to determine if i should really use a different grit when
: using a DA sander...220 sure feels like 400 by fingertip.

The correct test here is to see if the next grade smoother paper will remove the scratches left from the paper you just finished sanding with. So if sanding with a machine with 220 were to actually be like sanding by hand with 400, then you should be able to easily remove the scratches in the wood with 600. Do the test for yourself and see (not a bad way to learn btw).

Bill H.