I like using downcut bits, I normally cut hardwoods, and onion skin the parts. A downcut leaves a nice sharp edge on my parts.
But I am finding that they don't seem to last long. In hardwoods I normally use a 1/4" bit, .25" DOC, 18000rpm (Spindle max speed) and 150 ipm. Cut part .01 oversize and follow with a full depth pass to clean up. Dust collection running.
With a new bit I get a real nice finished surface I'm not sure how much I cut but it seems like my downcuts don't last as long as my straight cuts.
So what bits have you used that have a good tool life?