I use either SPD or Look Keo, depending on the type of riding I am mostly doing. At the moment it is Look Keo, as I'm mostly riding with little walking at any stops.
With single sided pedals, there is a knack to getting clipped in with the second foot. I find it is easiest if I start off slowly, and can usually get the pedal to flip over and get clipped in first time. The biggest issue tends to come when I need to get away quickly, such as when at a junction when having to clear a lane or two of traffic in short order. I get going without clipping in the second foot on those occasions, but then it can take a few attempts to get clipped in at a faster pace once clear of the junction.
For the number of times you might clip in during a ride, I wouldn't make the slightly more difficult process with a road pedal a determining factor. Comfort whilst riding will far outweigh that.
As an other option, rather than switching to road pedals you could look at stiffer soled SPD shoes.