I've been semi-following the developments of colour wheels for photoshop since the near beginning (Happened to drop in this sub-forum at the right time). I'll get right down to business:
Len White/Vorp's colour wheel:
Have not used this extensively (If hardly ever), so I cannot comment other than that.
Anastasiy's Magic Picker:
The most versatile of of them all, perhaps.
-RGB/CMYK/HSB modes, lots of them.
Occasionally, the registration information will need to be re-entered, as the program will default/reset (No idea why). Do this enough times, and the registration information will lock up. And you'll have to send an email to Anastasiy himself asking him to reset it.
I've used Anastasiy for all the longest of times. After I tried to use Len White's, but unfortunately at the time, it didn't work for CS4 or 5. I have no complaints, really, only perhaps a few slight performance improvements.
A lot more slick - "feels" faster.
Similar core features to Magic Picker, but a little less versatile.
No registration issues like Magic Picker.
Can't quite think of much at the moment. But I could find something.
I have not used all of three extensively, but I will to see how each of the 3 fare compared to each other.