I too have old 1/4" shaft bits that sit in my router table bit drawer but will likely never get used as they are the non carbon high speed steel bits and dull fast. Aside from that the only time I use 1/4: bit is with the trim router for lite work. But as with all bits, speed should be accounted for depending on bit size as well as depth of cut. I never take more then 1/8-3/16" off in a single pass if I can help it short of stile and rails or raised panel doods. On raised panels it's usually 2-3 passes.