Hmmm, sorry man, I've only used the PK Vortex, so I can't really compare, although I will say that the Vortex is very powerful, although it is possible to break if you drop it a few times.
I have a couple of different kinds of pk rings. I don't think that any are significantly better than another. I like to use reflective and durable over magnetic strength because of what I am using it for.
I use a silver one, and I absolutely love it! I haven't used any other, but the Wizard G2 does the trick for me anyway, so I really have no reason to try any others out (yet...if the G2 ever fails me, i.e., breaks, I'll be more open to trying a new ring, heh). It's been great so far, though.
Great rings, wedding band style. Prices are very good and quick delivery. I recently bought two, difference of one size between the two just in case. The smaller of the two was a little tight, but the larger ring was perfect. Just make sure you provide an accurate size and you're all set.