I used my router the last time with a 1/4" bit and it worked fine. I
just had the problem of having to shim the plywood as it was too thin
(5.2mm). I assume when you say too slow you mean feed speed. This is
not a concern but notably I have a Craftsman tablesaw that I don't
trust much in the way of square and clean cuts and a porter cable
router that is always perfect.
W