Not to keen on the MagicGate stuff (supposed to be faster then standard read times for MS sticks) but I can tell you about the CR5400 as I have two, one in my slim with a Class 6 16 Gig in slot one and a Class 6 8 Gig in slot two, and the other is in my phat with two class 6 4 gigs. They work fine, not as fast as my Sony 8 gig MS but fast enough.. (video never lags!!!)
Both PSP's run 5.00 M33-6