I used to everything using cutter comp. Since I started using CamBam, and running it on the same PC that runs Mach 3 I don't bother. It makes way less mistakes on tool paths than I ever did and it is really quick to make changes. Cam is what is making CNC a hobby tool.
Actually I would think that the low cost of real processing power will make the Mach 3 & 4 method of doing things become obsolete. The Windows computer or even a cell phone could be relegated to just the user interface with no timing issues and running Cad and Cam. The CNC would do 100% of the motion control like the pro machines do now. Heck USB sticks go to 128Gb! I am already using one that even has a display built in, a jog wheel etc, no PC. Limited capability, maybe 700 lines, terrible editing, but has been running a task continuously for 4 months straight right now.