The HUGE plus of the M520 is that you're shelling out £20 to try them out - they're simple, and doublesided, so clip ins are easier.
I'd be wary of paying more for something where you have to flip the pedal or negotiate a cage to clip in for my first clipless, personally, but ymmv, as they say.
yeah, i know what you mean,, but some of my 'avoid roads and hills' commute is off road and if i dont want to go with the spd, then i dont want to have to change pedals ..
dont see any diff between the 520 and 424 online though,, both seem to be 30 quid ? ? (at least , judging by lowest price on google,,,)
( gah, i'm probably gunna need another new tool arent i )