I'm using a Denon DP-59L now, because it has the auto shut-off which I find very useful. Compared to my VPI HW-19 with SME 309 arm, though, the sound quality is admittedly somewhat lackluster. I suspect, as Johnss mentions, that the primary culprit is the arm wiring and or arm connectors. Also, the factory hardwired interconnects are substandard. Unfortunately, re-wiring these would be quite difficult - not really worth the trouble. But there are improvements you can make short of that. You can dampen the platter and plinth, and if you're handy with a soldering iron, install much improved interconnects.
The Dynavector is an excellent cartridge - you can spend a lot of money and get one that sounds different, but wildly better - I don't know about that.
Seems to me that the largest potential improvement is the phono amp.