Today I stumbled across some end mills that were too good a deal to pass up. NOS, 12 of then for $2 each. Unfortunately they have 3/8" shanks. I don't have a router with a 3/8" collet. Festool sells one for $48 and Porter Cable has one for $15. But, I can buy an adapter sleeve that reduces 1/2" to 3/8" for about $12. Seems to me that is the way to go. Then I can use any of the bits in either router. I know there might be a slight increase in Run out or other slop, but I don't think it will be enough to matter. So, what Am I missing?