First question is "What do you wish to cut"?? If you're planning on cutting HARD material, go with carbide, if you're looking for general purpose cutters, I prefer tool steel because I can get a better finish than with carbide.
Carbide DOES have a place - there are materials that'll dull tool steel in a flash that carbide will just happily cut through!
For general purpose work - and especially thread cutting, I almost always use tool steel! Several years ago, I came across a jig advertised in Home Shop Machinist called the "DIAMOND tool holder". I think it cost me about $110.00. It was worth EVERY PENNY!!! It comes with a 1/4" tool bit holder and a grinding jig that makes it a snap to grind a toolbit for general purpose work and threading. The result is a razor sharp edge that I had trouble getting when sharpening by hand. When I say "a snap", I'm talking about sharpening a thread-cutting bit to an exact 60 deg. profile in less than a minute! As a result, I always sharpen my bit right before cutting a thread. In the past, I'd try to limp along by touching up my cutter and hope I wouldn't get too much swarf! You might want to take a look - I think they still advertise in HSM!