I wouldn't judge a keyboard by its technology ("mechanical" vs "membrane".)
"Feel" varies greatly even within a catagory, and you pretty much have
to try them out to see whether you like them.

When I upgraded from 286 to 90Mhz pentium, I kept my old keyboard.  I may
do the same with my recent upgrade to 266Mhz PII, although I'll have to
find an adaptor to go to the PS2 style connector (even the 286 vintage
keyboard have XT vs AT mode, and the ps/2s are just AT with a different
connector, right?)  The thing that seems to bother me most about the new
keyboard is that it's too light, mass-wise.  Sigh.

BillW