I'm new to road biking this Summer and have been clipless for just over a week. I have to say that in just that short time I've quickly grown to adapt and really like clipless (despite even having one fall because I couldn't get unclipped in time!). In fact last night was the first time I'd ridden without being clipped in (I got a dual-platform pedal) and it just felt really weird... I didn't like NOT feeling attached to the bike and it did make me notice how much more inefficient I was not being clipped in. I think the biggest thing that will take getting used to, obviously, is clipping in & out. I'd say you'd need a minimum of 3-4 rides to start to feel comfortable in them, but definitely be sure to practice clipping in & out and adjust the tension if necessary.

BTW, if you're interested, here are the pedals and shoes I got both of which I like a lot.