Jelco SA 250ST vs Jelco SA 750D

I have an Avid Diva II which came with the Jelco SA 250ST arm. Would it make sense to upgrade to the Jelco SA 750D or should I just leave well enough alone. My system sounds very good with the 250 and for the money it can't be beat. I was just wondering if there would be a noticeable improvement with the 750. It would be used with a Clearaudio Maestro cartridge. Any thoughts on the subject would be greatly appreciated. Thanks.