I had a WX 500 that displayed on my 530 as well, great set up! I don't think I would spend what it takes to put one in, but I would spend a couple bucks to keep one working.
If I could only have one of the three in order of importance to me for my flying:
1. XM weather
2. live radar
3. Storm scope
Not many good options for on-board radar on light singles. The general consensus seems to be that the 'in wing' version with the cropped antenna offered on the Bonanza for a while was rather useless. I know one guy who flew a lot with the pod on his T210 and found it a useful tool. The TBM, PC12 and Caravan have a pod on the wing, I am not sure whether their antenna is larger than what was available for the 210.