Making the transition to clipless and have read many posts on this forum. A single sided pedal (SPD) with a platform on on side (Shimano A-520) has the advantage of being able to be used with either clipless or regular shoes. Some posters indicate that it is harder with these single side to clip in since the clip side may not alway be upwards. Shimano also makes many double side SPD pedals but then of course you sacrifice the ability to use with plain shoes.

Overall for a beginner getting use to clipless what's the best approach, single or double sided pedals?