Spiral vs Straight Bits
This is the verdict: straight cutting edges are good only for stirring coffee.
Read more about the superiority of angled or spiral cutting edge profiles over straight profiles.
This is an explanation why you want to use nothing other than a spiral upcut bit when cutting out patterns (such as electrical boxes, windows, or various apertures through sheet material.
Note that guide bearings allow you to not destroy the material below in case of underside templates (ex. window cutouts). For overlaid templates, you can achieve this with Router Bushings. And, if a spiral upcut bit has no guide - can't its smooth shank function as a guide if the bit is sticking out far enough?
The last frontier is the plunge - where are the spiral upcut bits with plunge tips so that you don't need a plunge base to penetrate? As of 7/23, I have not seen such a bit - MJ. Another one of those fundamental 'why doesn't it exist' dilemmas - with the answer being that people do not mind the quick drilling of a pilot hole. Pilot hole drilling is not acceptable in production at OSE, according to the promise of industrial productivity on a small scale.