"Leon" wrote in message news:TZmDc.8989
Some plunge routers can be adjusted for height with the router under the
table--the plunge mechanism becomes in effect a router lift.

Huh? Unless you disable the springs, the plunge routers become twice as
heavy to lift or adjust under the table. Now if you are talking about the
fine tune adjustments that some plunge routers are capable of making, I
agree.

You're right it is harder to use with the springs still in, but if you only
have a few different profiles to cut, then the one or two adjustments even
with the springs in are not that difficult. I've got a Makita 3612BR and for
those times when I know I'm going to have multiple adjustments to make, I
remove the springs first and after that, all adjustments are really easy.