i would say the two most popular road pedal systems are Look (in the form of the new Keo's) or SPD-SL (in the form of the shimano 105/ultegra/dura ace pedal). they are pretty similar designs.

the pros for these pedals:
-larger cleat platform is more stable and spreads the pedal load better (no hot spots and better weight distribution)
-better engagement mechanism.
-higher quality bearings

cons-
-no double sided entry
-harder to walk in. (especially the look cleats, unless you carry cleat covers. the ultegra cleats have rubber tips and are a bit easier to walk in.)

i made the switch from SPD to SPD-SL and didnt look back. if you're riding road and arent walking around TOO much, it's just a much better pedal choice. just recently i switched from ultegra pedals to the new Look carbon keos and like them as well. i would say, however, that there isnt too much of a difference between the ultegra pedals and the new looks.

I haven't tried look or SPD-Rs. I just use SPDs, because I often have to walk, and don't want the awkwardness of a large cleat sticking out from the bottom of my shoe. So I use MTB shoes with SPDs on my road bikes.
Rich

Look was the first clipless pedal and I jumped on it when it came out, (still have the pedals on my fixed gear bike).

I tried the Shimano cleats, but could not get used to them after years of using Looks.

Yes, the Looks are hard to walk in, but I carry cleat covers, and don't combine hiking with biking, so it's just my front steps I have to deal with.

I went from mountain shoes to using shimano dura-ace (ultegra are similar) pedals. I think they are great. No cleat covers required and I don't have a problem walking around in them.

"...a lot of good riders use them. i use speedplay zero but they're not the best for walking even with cleat covers.

don"

"""I am new to the sport and have been using SPD clipless pedals. I ride a road bike but have the ""mountain"" shoes since I ride a lot in the city and need to walk on the shoes sometimes.""

What don't you like about SPD pedals, and what advantages do you envision with Look?

SPD pedals are ideal if you have to walk, and most of us do walk. I started with Look pedals when they were the only game in town, but switched to SPD a couple of years ago.

If (like me) you don't like ""mountain bike shoes,"" get SPD road shoes with recessed cleat such as the RT-50 below. It has a good stiff sole to prevent ""hot spots"" but no clunky mountain-type sole.

http://penncyclebuy.stores.yahoo.net/06shshsh16.html

""Chainwheel"""

IMHO, you're not missing anything with the SPD's compared to road style pedals. I prefer other MTB pedals to SPD's but not other road pedals.

I went from SPD's to Speedplay Roads, to the large Dura Ace roads. But what I really fell in love with are Speedplay Frog mountain bike pedals. I now have them on my road, 2 fixies, and mountain bike and totally love them.

I don't worry about tripping down the marble stairs of my building and can walk in them without spazzing out. They have a lot of float (good for the knees) but still have a secure feeling.

I can do track stands on my fixie and get out of them mid fall if necessary. When on singletrack I don't hedge and pop one cleat out on tricky sections like I used to do with SPD's. I'll stayed clipped in with the frogs through the hardest sections. I don't notice any issues with hot spots due to the small contact area. And I've ridden many 100mi rides on them.

I still use the Dura ace every now and then cuase I like the shoes I have them on. But I feel there's very little advantage other than a more secure of a clip in. That gives a little more security for racing I guess. But the negatives outweigh the positives. For me safety trumps all.

But it's all personal preference. Just don't give in to fashion and get look/time/shimano's cause everyone else has them.

You will find this topic endlessly debated on roadbikereview.com, mtbr.com, and here.

-Bill

I have two road bikes, one with SPD's and one with Time RSE carbon pedals. I like them both and frankly I don't see a big difference between them. The Times don't have dual sided entry, which is a slight shortcoming, but they have a good large platform. (NB - in the Time pedals, I recommend the carbon pedals over the composite ones - I broke those getting in and out.) I have SIDI mountain shoes that I use with the SPD's, and they have a good stiff carbon sole, which compensates for the smaller platform. Strictly road shoes are probably somewhat lighter than MTB shoes but you'd have to check the mfr websites for that. BTW, I have no problem walking in the Time cleats.