David: I don't think that the Dorian should be much worse than the Helikon when it comes to noise or sound quality. After all, although the Dorian doesn't use the custom stylus profile of the Helikon, it still uses a Microridge, which is one of the best non-custom stylus shapes that money can buy. And although the Helikon has more mass in its mechanical structure and is made of a different alloy, the mechanical concepts are one and the same for both designs.
But in general, my cartridge designs are intended to dump the vibrational energy (created by the stylus tracking the LP groove) into the tonearm in as direct and complete a fashion as possible, so a better tonearm may pay greater dividends than with other manufacturer's cartridges.
I would suggest trying a different arm with a less resonant mechanical structure, and/or one with less bearing play(IME, less bearing play means more for sound quality than low bearing friction). A more compatible tonearm can also help address any sense of brightness or leanness with the sound. As another tweak, you could try to add some weight to the headshell. The Dorian is a few grams lighter than the Helikon, and sometimes a heavier cartridge and headshell combination works better at controlling vibrational energy.
The other obvious factor that can affect the perception of noise is the phono stage. Pops and ticks are very close to impulse signals, and you can hear a big difference in how different phono stages deal with them (and RF interferance). Normally I don't recommend loading down our cartridges so heavily, but sometimes it can be a useful tool if the phono stage has performance/stability issues at ultrasonic frequencies. I'd suggest around 300 ohms if your phono cable has low-capacitance, but be willing to move down to perhaps 150 ohms if your phono cable has higher capacitance.
hth, jonathan carr