so, for years I used a mach 3 and edge shaving gel. then I heard all on the internet about proper shave technique, using a single blade razor, and a brush, and fine shave soaps.  Using a headblade because it has two blades and less irritation. and you know what?

  I have had more irritation than ever. with a mediocre shave at best.

   I give up!

The whole endeavour seems to be more art (mystery? / magic?) than science!!

With a two-blade cartridge - I cut myself to ribbons. With a three-blade cartridge - an exceptionally smooth shave (both used with a headblade). I like the brush (I suspect my hands flatten everything). I appreciate a warm lather ... but I tend to mix ingredients in the quest to find what works better. The best shave is always after I've skipped a day (doing the deed, and especially the finished result).

Don't give up - stick with what works for you. But occasionally experiment when you have the inclination to do so. What works brilliantly for one person doesn't always work out as a 'cure all' / 'holy grail' for everyone else. I've also discovered that doing something new means I don't always do it right first time around. I'm easily accused over over-analysing situations, so I usually dissect my failures at some point and attempt a new angle of attack ... and have seen some dramatic improvements!

I've never had any problems with my Mach 3, so I feel no need to change.