since we are kinda on the subject. I found what I think is a good deal. A 100mm macro 2.8 NON-usm plus a 50mm 2.5 for under $250...would i be able to get allot of use from the non USM? my 50 1.8 isnt USM, and the focus speed doesnt bother me, but my USM kit lens is pretty quick. I really dont notice much of a difference in speed between the 2 in focusing unless close ups, orlow light.
USM wont matter much for 100mm macro IMO. I focus manually most of the time anyway. Under $250 is very good price, but I am not so sure about that 50mm 2.5. which lens is this ?