i've only had experience with SPD and no other systems...

i like it best because it seems more universal, meaning: my MTB clipless shoes are SPD, i go to spin classes and the bikes' pedals are SPD, my DZR "casual-look" clipless shoes are SPD, etc.

anywho i have a number of bikes, and most have SPD pedals.

i have a520s and a600s on my longer distance road bikes and track bike....they are the single sided SPD pedals with platforms. i cant tell too much difference between the two, other than aesthetics (the a600s are a darker gray and a little nicer looking). I like the platform on these because it seems to offer more surface contact between the pedal and shoe.

i also have the m520s, the doublesided ones on my more commuter oriented bike.
I really like these honestly...they are the first SPD pedals i've owned, and they were hand me downs that were on some other bike for years.
Really easy to get into, because you dont have to look down to clip in.

with the single sided ones, it can be slightly annoying at many stop lights.


so the singlesided ones are nice for the platform, but if this is a commuter bike id say go for the doublesided....and honestly, they are probably way easier to learn clipping in on. can probably be found super cheap used on ebay.
i would suggest going that route for a first go if you are at all a little nervous about learning how to clip in