Ortofon SPU, cased or nude?

I fancy trying out an SPU, I have the right arm for it, an Ortofon 309D. I have searched the threads, but can't find a discussion of the difference between the conventional SPU in a case and the few N versions. There is quite a big saving, going for the latter. I would probably go for the Royal. Can anyone comment? thanks
There are other almost pure analog forums where you might find the experience you are looking for. I am a little surprised no one here has said anything. I know nothing about the cartridge you want to try except that the Ortofon SPUs had their own shells. Are you going to try the "naked" oned or the mounted one?
I was looking to try the naked ones, if there is no performance deficit, as they are quite a lot cheaper.
The SPU G shell carts get much of the effective mass they need from the integrated headshell. They weigh around 30g dependant on model. The naked N-series carts still need that mass so you'll need a very heavy headshell/tonearm combination to get the best out of it.
As an Ortofon dealer, we have enjoyed the opportunity extensively tested most of the SPU cartridges. Lencotweaker nailed it - the SPU A/G/N cartridges all sound different. There is actually a lot of technology in the headshells for the G series, which accounts for the cost difference.

Also, the G and N series cartridges with similar names do exactly correspond - the G series has some newer technology and designs.

In general, I would say that, like for like, the G series sounds more "SPU-ish" than the Ns, the latter which I would categorize as more neutral and less full and lush sounding.

The key to selecting an SPU cartridge is NOT to choose based on price, but to evaluate your LPs by genre and style (early 50s mono jazz vs. early 80s stereo hard rock and select based on the most appropriate SPU stylus type.

If you were looking for one cartridge to start off with, and if you have the right tonearm, I would recommend the SPU Classic GM E MkII as a great entry into the SPU system, for a reasonable price.
That is very helpful indeed. Thanks all of you
I think you and I have the same table and arm. I would get a G SPU since you have an adjustable arm board. I just got the Synergy and it's pretty incredible! I think I'll get a mono at some point too and then have simple cart swaps with no adjustments.
No adjustments in theory but practice might prove a different story. I bought a Royal GM II (which I adore, BTW) and Mono GM II with the same idea in mind. Turns out the overhangs are slightly different, requiring an adjustment of my SME arm position to get the alignment right. Fortunately, SME's slide-mount makes it easy, since my arm board is fixed.