Shelter 501Mk2 or ZYX R100-02H

I`m in a quandary...

Shelter 501Mk2 ($938) or ZYX R100-02H ($860)... Which cartridge is preferable for me?
I use: Avid Volvere turntable + SME-309 tonearm + EAR-834P Deluxe and I listen rock music (from art-rock to metal)...

I hope for your help...

Not sure I can help with that specific comparison, but you might want to contact Mehran at Sorasound to get an idea of his impressions. dougdeacon here has also written a good deal about ZYX carts, you could look at some of his post too. Not sure if he listened to the R100.

Also, I get the impression that in general, the low output ZYX carts are more highly thought of than the high output.

Again, NO direct experience here, but these were impressions I picked up when considering the purchase of a 4D (which is freaking incredible!).
Thanks for the advice, but Sora Sound is interested party...
Opinion of Auduogoners is more interesting for me...
On an Avid the ZYX will be too live and revealing for Rock. I would go for Shelter.
I contacted the seller of the cartridges... 2juki from eBay...
He answer me that ZYX R100-02 with a low output is better than Shelter 501Mk2.
His response word for word: "ZYX R100-02L will be better, you can get more sweet and warm sound from song and detail from music".
Yes, but more info even from an interested party is still a useful data point. The mistake is to not take into account just that party's opinion.

Not sure if Pani has heard the specific cart in question that you are asking about, but from reading XYX reviews it seems that they differ across the range with regard to the how live and revealing ia specific cart model is. For example, see dougdeacon's review of the 4D, where he compares it to the UNIverse and concluded that the 4D is a better rock cart.
I see the following advantages in cartridges:
1) the abundance of solid bass, drive and perseverance in LF;
2) high degree of detail and comfort of a mid-range;
3) a fascinating silkiness of HF;
Sorry for my bad English...
BTW; 2juki is a very good guy. I think he used to sell here on Agon. Highest regard.
I have heard the ZYX R100 on Avid Diva and Acutus. I used to own a ZYX RS30-02 low output version and played it on my Verdier extensively on a variety of tonearms. The ZYX are a champ at bass and PRAT but it lacks a certain warmth and sweetness in mids and highs which is so very much required to enjoy rock. The ZYX is a reference to me for classical music and well recorded Jazz. The 4D is best of the lot for rock, I agree but that is expensive. I had a Denon 103pro prior to ZYX and I enjoyed Dire Straits more on the Denon than on the ZYX, just to give you an idea. The Shelter falls more in line with Denon. In fact it is supposed to be a default upgrade for Denon users/lovers. Hope that helps.
Both are good sounding cartridges, Their character will depend in your Phonostage and Frontend in general too. From my memory the shelter shows a good Bass, full tones, the Zyx shows more detail and is generally a bit different in overall Balance. It has a short Diamond which collects dust easily, so some cleaning should be done more otherwise the higher frequencies suffer. But this is no big deal. I think, the Zyx has a longer life, Shelters can go down pretty fast, I had two on loan which started to get weak and they didn't have so many hours on it.
Yes, the ZYX has a long life. Good for at least 2000 hours and even more.
OK, this is useful information...
As I said, I have EAR-834P DeLuxe.
And pair of tube amps - Audio Research LS/VT.

I don't know where you got that information but it doesn't match ZYX's specs or my experience.

I've used over a dozen ZYX models in the last ten years (Bloom, R100, Airy 2, Airy 3, 4D, UNIverse, Omega, UNIverse2... in all three coil materials... in both high and low output versions).

They all measured/behaved like 12-15cu cartridges, as specified.
Ok, I thought the ZYX were measured at 100hz so recommended to multiply stated compliance by 1.5-2x.
Cartridges of 22-30cu compliance tend to perform best on fairly low mass tonearms. That is not the case with a ZYX. On a low mass arm (say < 10g eff. mass) a ZYX tends to sound lifeless and bass shy. Instead of the arm stabilizing the cartridge, the (relatively stiff) suspension wags the arm.

ZYX's sound best on mid-weight tonearms, roughly 11-20 grams or so. Optimal performance (fullest bass and dynamics without overdriving the cantilever) seems to occur on arms in the 15-18gm range.

FWIW, resonance tests using the HFN&RR test record and my TriPlanar (~11g eff. mass) put a ZYX's vertical and horizontal compliance in the "desirable" 10-11Hz range - as expected. A 22-30cu cartridge on this arm resonates at higher frequencies.

Note: all this is with ZYX's that had the optional "SB" weight. A ZYX without that weight would only be optimal on a fairly massy tonearm, say 20gm or above.
I have a shelter 501 in a box, on the shelf, with all the other retired but still good audio paraphanailia I am collecting. The shelter was great, until I upgraded my phono stage. A couple xmas's ago I gifted myself a fosgat(from santa). The next morning I hooked it up, turned it on, cued up Hungarian dances....anticipation became lunch bag let down:(.
Instead of giving up on the well regarded fossgate, I bought a nice used zyxs airy 3( right here). After installing I repeated above process...and was happily blown away.
Sadly I don't know the r100. But I am planning to have santa bring a new airy 3 this year:).
Moerch recommends their heaviest armwand (the Blue, effective mass of 14g) with the ZYX carts.

As an aside, my do I love the Moerch's feature of swappable armwands of different mass (from 4-14g!).