Cartridge / Tonearm opinions requested...

If you do want to start thinking about a top notch phono stage, then start thinking about an Aesthetix IO. Then you can stop thinking and start listening to music. You won't find anything that is going to beat that. If you can afford to go with the IO Signature with Dual Power Supplies, then go with that. It has enough selectable gain to take any cartridge direct-in, and has the best sound quality I am aware of. It is right at home in the highest of high end systems.

If you are open to other choices for tonearms, I would strongly suggest the Origin Live tonearms. I use the OL Silver on my Teres, and it is a stunning performer. Personally, I feel pretty strongly about using a gimbal-bearing type tonearm with low compliance cartridges, which you seem to prefer, judging from your list. At the prices you are looking at for WB tonearms, you could get the top line Origin Live Illustrious. Make no mistake, these OL arms are at the top of the heap. They may not get the press that the other top arms get, but it is likely that they will outperform most of the more well known top arms. My OL Silver works beautifully with the Teres, and I have no desire to change to SME, Graham, or anything else. It's a perfect match for a Shelter(which I am using now), or Koetsu, or any other low to mid compliance cartridge. Don't let the lower price scare you away. These are some of the best arms you can buy.

I recommended OL arms because I much prefer gimbal-bearing arm designs. I like low compliance cartridges, and there is no question in my mind that they are handled better by gimbal-bearing tonearms. Yes, some unipivot arms have made improvements in stability by using outrigger bars, but they remain an inherently unstable platform, due to their single point bearing. Just my opinion, but it is derived from over 30 years experience with analog equipment.

I have gotten emails from some Audiogon members stating that they got good results using Shelter cartridges on their WB arms. The WB arms have stabilizers, and should do better than basic unipivots with a lower compliance cartridge. I think you're reasonably safe with the Shelter or Koetsu or WB cartridges. I don't have any experience with the Allearts cartridge.

As far as the cartridge choice goes, that is pretty subjective, and may have budgetary considerations. I think the Shelter 901 is a terrific cartridge and costs far less than any of the other ones you mentioned. If you want to venture into higher-priced territory than that, I would use the Shelter as a benchmark, and audition the others against that, to see if they can beat the Shelter enough to make them worth the extra money. I think you'll find that the Shelter will "hold its own" against just about anything, and is alot easier on the wallet. But, if you find that you like one of the others better, and want to fork over the dough, then at least you've satisfied yourself that you got more for your money by comparing against the high-value cartridge. I've seen people get a little upset when they have bought a very expensive cartridge, and found that the Shelter would have done better for alot less.

I would also add a ZYX R-100 Fuji to your cartridge list. This is a very fine cartridge, about $2k, and is competitive with the Shelter 901. The Fuji is slightly better on small-scale music and the Shelter is slightly better on large-scale music, and the bass response on the Shelter is absolutely first class.