Go for the Krystal, it’s an excellent cartridge and streets ahead of the Adikt ( I have both in different LP12 ‘s)
At same time I would upgrading your DV phono stage to the Mk 4 - friend of mine has just done this from the 2 like yours to the 4 and again huge improvement
I auditioned Adikt and Dynavector XX2 at the same time with the DV phono stage and felt the XX2 was definitely worth the extra. I’ve not heard the Krystal but by all accounts it’s a great cartridge and a good alternative to the XX2. With your system you will certainly appreciate the difference either of those cartridges make over the Adikt. Value, only you can judge.
No one has mentioned the Dynavector Karat cartridges. I’ve had two 17D2 MkII and a D3 on a similar spec LP12, my current one is due for replacement and I have been auditioning the Krystal which has great speed, dynamics and musicality but I find its top end lacking the sweetness and refinement of the DV 17’s which have similar speed and dynamics (PRaT). The Krystal by contrast can to my ears be a bit fatiguing and strangely inconsistent.
I’ve tried a DV XX2 II which to my ears was completely the opposite of both DV17’s and Krystal leaning more towards a warm and coloured presentation. I’m hoping to now audition the latest Karat 17DX.
My LP12 is Klimax Radikal, Keel, Karousel, Ekos SE/1 Naim amplification and Allae’s
Phono stage is a Naim Prefix/Hicap which might be proving to be a limiting factor due to its limited load options.
In short, what I’m saying is, if you can try a DV 17DX, £50 cheaper than the XX2 II and now due to the price increase significantly cheaper than a Krystal.
The Karat 17’s are superb cartridges to my ears in a Linn/Naim system and have improved a lot over the years (they also ime dont wear out any time soon) and the DX is claimed to be the best yet.
Just to add that I’m lucky to have a very patient dealer willing to install different cartridges and listen to them at my own pace at home in my system.
Sometimes a dem model, sometimes a new one which he’s happy for me to run in!
Seriously though, it’s really invaluable and important to be able to hear a cart in ones own system setting without pressure. Probably more so than any other component. First impressions at a shop dem room can be very hit and miss, for example the Krystal on first impression nearly had me reaching for my wallet but given a home audition on my LP12, system, room…