I've heard better arms but never compared directly in my own system, and the better ones are much more than I'd care to spend.
I've read of a direct comparison with a Michell Technoarm, which is more than twice the price on this side of the Atlantic, and the user preferred the 750D.
Link below is to a comment from someone who went to the SME V and found it to be better, but not what he'd consider to be any kind of high value purchase (the SME)-comment is about halfway down the page.
http://theartofsound.net/forum/showthread.php?18684-Jelco-SA750D-tonearm-is-it-that-good/page3The Audiomods is kind of the hot arm right now, but the tweaked Rega thing doesn't do it for me, especially the lack of any azimuth adjustment.
The 750D has every adjustment you'll need as mentioned earlier, has excellent build quality and also has flexibility in terms of using it with an upgraded headshell or one lighter and more appropriate for a high compliance cartridge, although even a reviewer in one of the British audio magazines commented on how really flexible the arm is with a wide range of cartridges. The fluid damping is a big plus in this regard, as well as the optional heavier counterweight.
Nothing really comes close in terms of value in my opinion (I've owned the arm for about 5 years and have no intention of upgrading) and the "non-black" version which I have (it's kind of a cross between chrome and champagne, almost a pewter finish) is also really good looking IMO.