Update (not that this issue will ever be closed for some people)

I accidentally ordered m530 spd pedals -- twin-sided spd -- instead of dual paltform/spd a530's I thought I'd purchased. Tried them anyway.

Compared to having to flip the pedal, having the cleat lock on either side -- and having a shoe that doesn't just skid when you put it down on the pavement -- was quite a revelation. Digging it a lot.

Now I've received platform/spd a530's after all, and will be trying them on my other main bike. Thanks everyone for sharing their experiences, Bikeforums FTW again