I went clipless for the first time last week, I was persuaded by a mate to get the SPD SL version (single sided). I have done 3 rides on them and have adjusted okay and notice things seem tighter and more responsive still, compared to toe straps. The most awkward thing I have found is clipping my left foot back in when I re-start after having to stop, but seem to be getting the hang of that now. However, I did slip and crack my left ankle last time out, but nothing more than a bit of a bruise and some choice words at the time.
I am thinking about trying the MTB version on my other bike though, and possibly even replacing the ones I have just bought as well. The reason being that if you had to walk any distance on your exposed cleats, such as if you had a mechanical failure and couldn't fix it, it would be a nightmare and the cleats, and most probably the shoes as well, would be ruined, whereas with the MTB version the cleats are recessed, it seems, so an enforced lengthy stroll wouldn't be as expensive.