My two cents:
So, cycling for ages but never had SPDs
Commute, do city cycling and tour whenever I can (only just have my XTC)
Got Shimano PD-M324 double sided pedals for trainee purposes
Spring settings seem to be half-tight
Cleats are SH51 single release ones
So...I got on the bike first last Sunday after a quick training round in the front street.
And so far I found it easy to use. There was a bit of an emergency pull-out at the traffic light (green for 3 seconds sheesh..)
My two cents:
The pedal will easily unclip with your foot in the bottom position
So what I tend to do if I see a traffic light/ejit driver coming is get ready to unclip
I think of rotating and pushing my heel outwards...that seems to do it for me.
Mind you I got shoes of e-bay from somebody who couldn't get used to SPD...so you are not the only one
If you keep going you will get used to it no doubt ^_^