What is the appeal of the Denon 103 cartridges?

I had one for years.  It was warm, and enjoyable, much in the way that Grado's can be.  Like most cartridges, setup is the most critical - and probably means more than what one starts with as a hunk of diamond, metal and who-knows-what.
And, int he grand scheme of things, cheap.
I could listen for long periods and enjoy it. But more i wont say since it was many years ago.
Don't under-estimate a Grado Black or Green either.
G

Oh yeah.  I remember my Grado!  Could've easily have lived with it for the rest of my days. I even met Grado at a hifi show.

By audition, the Hana EL (at about the same price level) is better. You may wish to learn more about this amazing cartridge. 

Don’t under-estimate a Grado Black or Green either.

Comparing cheap Grado Black (or Green) to expensive Grado Signature XTZ anyone can understand why the cantilever and stylus profile make so much difference in sound. The difference between lower and upper range of Grado cartridges is huge. When a cartridge designer is making his top model it must be (and it really is) superior to the entry level models. But those models looks almost identical and even styli are interchangeable.

For the same reason anyone who paid a lot for an expensive cantilever (to replace Denon stock DL-103 cantilever and stylus tip) are all claimed the upgrade in sound quality is obvious.

Don’t forget that Joseph Grado invented first Stereo MC cartridge and patented it. But he’s making an MI cartridges simply because they are better almost in every aspect. His top Signature XTZ was $750 in the 80's. 

I had a Hana EL. Nice sound though far less dynamic than a modded 103. My favorite 103 recieved a new JVC aluminum cantilever with nude shibata and Stanley Engineering closed Cocobolo body. Just lovely sound. 

My all time favorite carts however are as follows 

1. Audio Technica ART9
2. Klipsch MCZ-7 (retipped with ruby cantilever + micro scanner II tip)
3. Phillips GP922 (FGS special retip
4. Supex SD900 Super (shibata retip)
5. Grace F9 (boron cantilever,  micro ridge tip)
6. Fidelity Research FR-7
7. Fidelity Research FR-1 Mk3F