Why do I like the Denon 103r so much?

I was using a VDH retipped Crown Jewel (aka Shelter 501) when I got my first 103R - and much preferred the Denon for its involvement and superior tone and texture and presence.
With this cartridge I find myself appreciating the music itself and how its being played - rather than the hifi qualities.
That said, the SoundSmith retip can greatly improve the top end (especially) and clarity in general. Focus, separation, recovery of ambiance and other soundstage dimension/details are also much improved. The stock 103R is a very good tracker, but the line contact retip tracking is significantly better. The musical qualities of the stock cartridge are essentially retained, though of course it does sound different.

Spirit, at some stage I will send a 103R to Expert Stylus so I can compare with the SoundSmith version. The different stylus shape will certainly have an impact on the sound. I've heard some say the 'Paratrace' stylus (similar to VDH's profile?) used by ESC is superior and sounds 'better'....but I've never read a controlled comparison. Since line contacts are fussy beasts to optimise, it would be easy for one to be slightly less well aligned for geometry/azimuth etc and the 'win' would go to the other.
Plenty of users with the ESC version and, like you say, it has great feedback. I'm sure you'll enjoy it.