Shelter 501 Mk II vs. Grado Statement Reference

I currently have a Grado Statement Sonata cartridge mounted on a Michell Tecnodec with Michell-modified Rega RB-250 arm. I am afraid I have upgrade fever and am considering replacing the Sonata with another cartridge. Although I do like my current setup, I am seeking a better soundstage and more airy highs. It's not that the Sonata is a bad cartridge in my application, but I am wondering what would be a good upgrade. Grado's "retipping" policy would allow me to trade in the Sonata and buy a Statement Reference for about the same price as a new Shelter 501 (about $800). How do these cartridges differ in terms of sound? It appears that the 501 has lower compliance and weighs a little more than the Grado. Is this an issue with my arm and table? My current Grado tracks just fine at 1.5 grams VTF. By the way, my phono stage is a Ray Samuels XR-2, so I can accomodate a moving coil or the low output Grado no problem, so output or loading isn't a factor in my decision. My music choices are mainly jazz and 70's rock. I have never had a true moving coil cartridge, hence my interest in the Shelter! But the Grado upgrade (retip) policy sure seems like a good deal. Any help in this decision would be appreciated. Thanks!
I'm inclined to agree with Stevecham's comment that you won't go wrong with the Shelter 501 Mk2. It's a fine cartridge, particularly for the money, and I strongly suggest you audition it before you make a decision.

That said, I own a Grado Reference (the 4.5 mV output version), and I love it. It is very musical, has great bass, smooth frequency response, very good detail (but not clinical, like some MC cartridges), and -- to my ear -- really excels at accurately reproducing the tonality and timbre of instruments. It also has excellent transient response (tho' not as quick as the best MC's) and fine sound-staging. To get better performance, you will have to spend around $2k.

The only "deterrents" to the Grado Reference are its susceptibility to hum (from proximity to the drive motor), and the need for a dead-level platter (otherwise, you may experience the "Grado bounce"). Mine tracks very well at the recommended 1.5 grams.
Agree with the others. A Shelter would give you the more extended highs you're after while retaining the bass and midrange heft you have now. The stylus profile alone compared to the Grado will do that.

Benz is another possibility in a mid-compliance cartridge.

If you do go with a Shelter or other low compliance cartridge on an RB-250, Twl's HIFI mod is a cheap, easy and utterly mandatory mod. You won't believe your ears. Check it out here:
The Shelter is definately the one to beat in that price range, but Grados retip/trade up policy is a great deal. I ran my Statement Sonata with a Dynavector P-75 phono stage thru the phono enhanser cercuit and have never heard a Grado sound more open and airy.
Thanks for your replies. So, is the Shelter not a candidate on my RB-250 arm due to the low cartridge compliance, unless I do the modification? My RB-250 has the Michell Tecnoweight and VTA adjuster installed, as well as an Incognito cable upgrade. The Tecnoweight has two available sizes (weights) to accomodate different cartridge masses. Is this sufficient to accomodate the Shelter cartridge, or would I really need to do the "Twl's HIFI mod"? Thanks again and please forgive my ignorance when it comes to matching cartridge compliance with my RB-250 arm...
The Shelter is certainly a candidate for your RB250, no problem. I had an RB600 on a P25 for awhile and the Benz Glider L2 also a low compliance worked just fine. Please reread my reponse above; the Shelter will work fine with your arm.