I agree with Tessla, all of our tanks are overfiltered, mainly because we keep Plecos but also finds it helps maintain the water quality.
Gpscott, I can see what you are saying about getting media and locally and cheaply but I also think the brand does matter sometimes. A lot of people have different experiences with filters and it's always handy to get a few ideas and opinions from members as to which they find is more suitable.
We have found Fluval ones to be great but I know some people have had problems with them. We have Rena ones on our 137G tank but we aren't as keen on them so we wouldn't buy another one if the need arose.