There's little practical difference. The 586-1 has the floating hand and radiused studs, both minor lockwork stuff. The 586-2 incorporated the updated firing pin and firing pin bushing in the frame, which was what the L frame recall was all about.
Check your frame, on the yoke cutout, below where the barrel screws in, where the model number is stamped. If yours has an "M" stamped there, it has had the recall update.
As for if one is more valuable than the other, it is hard to say. Collectors always prefer the earliest version all other things being equal. If they are both still unfired, in their original boxes with all of the original paperwork, the earlier one may bring a slight premium, but these guns are not really collectors items yet, being fairly recently made. Yes, I know, recent is relative.