In addition to reading responses here, it would be worthwhile to go to your bike shop and chat with the folks there. This is one area where I've found employees to be universally helpful.

I think it comes down to personal preference, kind of like saddles.

I'm very happy with the Ultegra SPD-SLs (look-style pedals) on my road bike. Easy in & out once you get the hang of it, very solid feeling, and I have the sensation of good power transfer (who knows though?). One drawback to this style of pedal is that float is either quite limited or non-existent, which can aggravate knee problems if you have them (I am lucky to have healthy knees). There are a lot of folks out there who love their Speedplays and Crank Bros -- which is great -- but sometimes I feel like look-style pedals get an unfairly bad rap from people who LOVE whatever other pedals they use -- and I would encourage you not to rule them out automatically because other people say that Speedplays or Candies or Frogs or whatever are THE BEST PEDAL EVER.

I have Crank Bros. Eggbeaters on my commute bike. They are better suited to the purpose than the road pedals (they allow me to wear mountain shoes, which are more comfortable for walking any distance, and this cleat/pedal combination does well in snowy or muddy conditions, when road cleats would get clogged). And they are very easy to clip into/out of. However, I like the SPD-SLs better and if walking some distance/mud/snow were not issues, I'd at least consider putting them on the commute bike. (Though I confess part of the reason I put eggbeaters on the bike is that it's a cross bike, and it would be a little weird to put road pedals on it... silly I know, but someday, maybe I'll actually try a cross race???).

The eggbeaters have more float, and are smaller, and both of these factors contribute to a **sensation** that I'm not getting as much power transfer, especially when climbing. (Though my roadbike has longer cranks and higher gearing, and this probably affects my perception of "power transfer" as well). Plus I like how solid the clip-in action on my road pedals feels. This is totally an idiosyncratic and unimportant thing for me to care about -- it doesn't affect the function of the pedal -- it just "feels" better to me. But once you're in, you feel like you're locked in, and I like that too. I've never come out of my eggbeaters accidentally, but it feels like you **could**, for instance, when standing to get started at a light when you're in slightly too big of a gear to comfortably start from a dead stop and you really have to jump on the pedals.

Remember you can always change pedals, and assuming your shoes are compatible with both systems, changing cleats is a snap and doesn't require new shoes. So it's not as big of a decision as say, getting a new bike . Of couse you know this, but I think pedals are one of those decisions that people get really super focused on for some reason (I certainly did for both bikes, and my bf obsessed about pedals to an extent that drove me a little crazy), and I think that can make it harder to make a decision.

Good luck!