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!