There are a few differences, I don't know whether you want to know about the routine or the actual make-up.
I'm going to assume you know the basic and I don't think it's exposure if I said that the mind-power deck was 1 banked and the radar-deck was 2 banked because you have to know what I'm talking about
If it is exposure please report this post or PM me so I can get rid of it.
With the Radar-Deck you can show the cards as pretty regular but it would probably not stand up to close scrutiny.
The Mind-power Deck on the other hand can be shown as a completely normal deck of 52 cards and (correct me if I'm wrong) but I think the spectator can spread through themselves too. - Note: You can do this with the Radar deck but it's not recommended.
In all honesty, I prefer the Radar-Deck over the Mind-power deck because I like the routine more. And you can really build it up to something incredible (check out Richard's performance on youtube)
Derren Brown has an astonishing routine using the mind-power deck on his DVD called The Devil's Picturebook. Maybe that's something you might want to look into aswell.
- Sean
P.S. Please bear in mind, I only own the Radar Deck and my knowledge of the mind-power deck is from watching performances and Derren's DVD.