Just thought I would put my bit in, but the only experience with clipless pedals is today. Got my first road bike today and used SPDs for the first time. The hardest thing I have found with them is clipping myself in; feeling around the pedals until I hear a click - it usually takes me around 10 seconds to click into both pedals (I feel a bit paranoid on public roads when this happens).
Unclipping from the pedals has been easier than I thought, I have had only one hairy moment when I came to a halt quicker than I thought and hadn't unclipped in which the ohhh nohhh feeling quickly followed as I seen the world tilting sideways but I just got the falling side foot unclipped in time before completely ending up on my side. From then on I have unclipped my best foot well before I stop. LOL.
Riding a road bike for the first time feels very strange after only experiencing hybrids and mountain bikes. The gear system is strange being part of the brake levers; using the brakes when using the top of handlebar having to reach down from the side, and the riding position feels a bit strange while holding the top of the bar and very very strange when holding the drop bars and feeling a bit unbalanced when getting back to holding the top of the handlebar ( I hope I dont fall off at speed).