In general, I would agree about a house sound with Dynavector, with the exception being the XX-2, and possibly the Te Kaitora Rua. I have had no experience with the Te Kaitora.
If pressed to choose between the 17d3 and the more expensive XX2, I would opt for the less expensive 17d3. This would not be true in all systems.
Here is the text of an earlier post of mine on the topic:
Of course, one would expect a manufacturer's more expensive cartridge to be "better", but in this case the 17D3 is far, far better than the price differential from the 20X would predict. I've even commented to the US distributor that I actually prefer the 17D3 to the more expensive XX2, and he couldn't disagree with me.
We both agreed that this preference comes down more down to personal taste than absolute goodness. It's also a function of the components you're matching up with this cartridge, and in this sense, I don't want the above statement to be misconstrued. My 'tables tend to control resonance very well, but a more "excitable" analog rig might not respond as well to a lively, bouncy, cartridge.
I can envision someone with a system that tends toward the bright side as considering the XX2 to be a far superior cartridge. In the context of their system, they'd be right.
In the 17D3 and XX2, it's as if Dynavector took two parallel paths toward the ultimate convergence occurring in the XV-1 series (the "s" and "t" models) - acknowledging that you can't have it all without heroic efforts and a commensurate price. I look at the XX2 as appealing to a fellow who's willing to sacrifice dynamics in favor of refinement. The 17D3 makes the opposite compromise.
While the choice between a 17D3 and the more expensive XX2 seems to be very system dependent, the leap up from a 20X to a 17D3 does not seem to be. You're not sacrificing any refinement in stepping up to the 17D3 from a 20X.
Disclaimer - I'm a Dynavector dealer.
Cheers,
Thom @ Galibier