I never will use a cartridge again, mainly because it was a joyless task. With my DE it's almost therapeutic, mind and body.
Not sure that I agree ... that may be true when you just started, but DE shaving becomes a routine as well ... at least for me it is. The joy is in the lather for me, not in the razor.
I've been DE shaving for over 7 months, been the same joy since day 1 for me. I love that there is skill involved, angles, multiple passes. I shave after my day, a great wind down. My choice has nothing to do with getting the closest or fastest shave, it's all about the ride.
I use a Mach3 when I travel that is about it.
While on vacation a couple of weeks ago I had a problem with my Slim and bought a Gillette three-blade disposable wonder, haven't experienced that much irritation since I had the Chicken Pox! I found a way to make do with the Slim.