What material are you cutting? Steel or aluminum?
We do most of our aluminum milling, with as we call them, Ski-Carb End Mills.
Solid carbide end mills set up in shrink fit holders.
We use Fullerton end mills, www.fullertontool.com
We do most of our steel milling ( 15-5 stainless ) with A-Symmetric solid carbide end mills set up in shrink fit holders.
We use Hanita end mills, http://www.kennametal.com/en-US/.../...nds_page.jhtml
Carbide insert tooling has places where it OK for some situations.
In our shop we get far better tool life and reduced run times using solid carbide.
For example, we were using .500 & .750 ingersoll insert end mills and we were just burning through inserts cutting the stainless.
We replaced these cutters with the Hanita solid carbide end mills and reduced the run times in half easily and in some cases 3-4 times faster.
Insert costs, time to stop and rotate, slower feeds and speeds along with the initial cost of the cutter and if you blow out an insert you can waste the insert pocket.
We send our dull end mills out for re-sharpen to extend overall tool life and to help reduce cost.