Nigel, I got the M520, which is double sided. Just thought it would be easier having 2 'options' at connecting.
Fitted them tonight but not yet ventured out. The shoes I bought are Shimano MO64 MTB. As with most Shimano shoes they come up small so I got one size larger and they fitted perfectly. Hopefully have a go tomorrow. Not looking forward to the inevitable fall at some stage, as detailed by Claud above! Hopefully the combination of new bike and clipless will have a positive effect. What did clipless do for you?
Brett, managed to squeeze in a ride this evening, on my old bike as the new one is nearly clipless. Just edged up the average a tad, though nothing to write home about. Do need to up the distance though.