MC Cartridge upgrade from Grado reference?

I need some advice on a cartridge upgrade. I currently have a Grado Staement Refence (.5mv) and would like to try a good MC. I was thinking the Shelter 901 would be the one to go for. I then started reading here on Agone and I am finding out it may not be the best match for my tonearm/TT. Any suggestions for 2k or under? The Helicon, for instance, seems to be held in a little less esteem than it once was (especially compared to the Shelter). How about Koetsu, ZYX........... (or stick with Grado (Statement????))

Current rig is: VPI Aries, JMW 10, ARC Ref. phono
I had pretty much the same rig as you (since upgraded to TNT HR5), and found the Benz Ruby a very nice upgrade. Like the Grado, warm and inviting, but with loads of detail. You can get it for $2,000 with ANY trade-in (e.g., any old, cheap cartridge you have lying around -- no need to give them your Grado).
I'd go with a ZYX R-100 Fuji for $2k.
So would I, IF I had the 2K. :-)
Can anybody tell me about any of the new Koetsu's? Are they in the same league as the ZYX, Helicon, or Shelter's (for the $$$)? I have reservations about the ZYX, although I have never actually seen one, it doesn't look that well made. Any thoughts would be appriciated.

Also would a Koetsu work with my JMW?
The Koetsu cartridges have a certain charm to their sound that puts them in a category by themselves. They are very good cartridges, and some people will only want the sound of a Koetsu. Others feel differently. They are expensive, and you have to pay a pretty high ticket to get into the Koetsu club. I am one that likes the Koetsu sound.

To find out if a Koetsu will work on your JMW arm, call VPI and ask them.
Koetsu, the "Pleasant Light" literally, is the best at conveying the emotion in the music. The mids are very special.