I have the Shimano A-530's (regular shoes one side and SPD on the other) on my nice road bike and some wellgo platform/spd pedals on my old Panasonic.

The performance of the A-530's is far above that of the wellgos. Clipping in and out happens without a thought-- crisp clip outs at every stoplight.

The wellgos have given me problems. I had to bomb through a stoplight around a city bus b/c of the wellgos. They still require much thought to clip in and out of, even after a few months with them. They seem to be very picky about the angle of force you apply to clip out.

The A530's are weighted just right so that the clip in side is positioned perfectly when the light turns green. Not so on the wellgos.

The A530's are about 20 or 30 bucks more than the 520s. The nice platform for riding with regular shoes, but they seem to have good performance too-- I ran a somewhat hilly century in 6h10 using them.

Jeez, I think I just convinced myself to buy a second set for my Panasonic.