MM Cartridge for Planar 3/RB-600 combo

Anyone care to share any experiences or opinions for/with a good MM cartridge for a Rega Planar3 with an RB600 arm?
I have been using a Grado gold with decent results, but I would like to know if there might be a better match. My budget is around $300.00.
The entire line up Ortofon's 2M series is supposed to be very good. I had the 2M Bronze which retails for 398 and really liked it. I hear the Red and Blue are very good too.
I have a Rega P25 with a RB600 arm that's upgraded/modded out the butt. I am currently using a SoundSmith retipped Grace F9E that's WONDERFUL! I have also had great success with the Audio Technica AT150ML and a Linn Adikt.
Roksan Corus black.......
I have this cart on my RB250 and it is extremely good.

I do not know this person, it is just a good deal...

good luck