I decided to go back to the M3 yesterday just to see what I would think about it after almost 2 months of DE shaving. I just the same prep and face lathered with a brush as usual. I took a brand new cartridge which I normally remember being amazed at how sharp they were.
I did a 2 x WTG and 1 x XTG and ended up with a shave that was as smooth as I get with the DE. However it was very clear that the M3 was really pulling on my beard. It was really weird to feel this as I've never thought about it before. In other words, not a very comfortable shave, with a decent result and some minor irritations.
I'll just stick to DE for a while more