Since I've bugged a ton of people regarding this I figured I'd share some feedback now that I have 2 good rides under my belt.

My former set up standard chorus 53-39 10 speed cranks and 11-23 cassette in the back. I'm a small guy at 5'6 about 147 lbs. and a decent climber (for a recreational rider). My problem was the long steep climbs (6% +). I could do them fairly well but I'd tire out way to quickly staying on the 39-23 combo and mashing at about 50-60 rpm.

Friday I had the 50-34 FSA mega exo SLK compacts put on my bike (kept the 11-23 in the back) and here's what I noticed as I did the same ride I did the prior week yesterday:
1) I have about 2 clicks more then last time
2) Probably psychological but it did feel somewaht lighter but not necessarily stiffer than my old chorus
3) If ever I probably went SLIGHTLY faster uphill
4) The key difference I was definitely feeling better rested at the end of the ride to the point where I'm a bit disappointed in myself today as I feel I may not have pushed myself hard enough. My heart rate would disagree but my legs seem a bit to bouncy after too hard rides.

Downside
1) I need to get used to the gears (as I'm not used to having the extra clicks) and timing when to use the harder gearing
2) Possibly on a downhill a larger/stronger rider you spin out on the 50 11 but that wasn't the case for me (but I thought I'd bring that up)
3) I'm still trying to work with being at the verge of cross chains

So in my humble opinion this is an awesome upgrade. Perfect for someone like me who feels that they have maximized their current gearing set up and would like to face even harder climbs with spinning option (but not too much). It will not make you faster per se but used properly it will keep you fresh for the push at the end.

I'm curious why you didn't just try swapping your 11-23 for a Campy 12-27 cassette. It would've given you about the same low gear, I think, and youd've kept a 53-12 for your high end -- at a much lower cost.

From a personal point I wanted slightly shorter cranks.

From a technical point the 11-23 is a tighter gear ratio than a 12-27, I would say that both accomplishes pretty much the same thing looking at the high and low end.

Actually if you get aluminum compact cranks you may come close to the cost of replacing your cassette.

I will add to this. As I posted a few days back I got the Ritchey WCS compact cranks and put them on my Salsa along with a 12-27 cassette. THis replaced an Ultegra triple with a 12-25 cassette. I have had 2 rides on the combo, 20 miles on Thursday and 50 miles today. At first I thought I was going to have some issues but after today I think I like it. Normally when I am in the middle of my middle ring on the triple I would be doing like 14-20 MPH. On the compact this range is right where you need to be thinking about changing rings. On the small ring I can do about 17mph before I spin out. There are 2 gears left on the cassette but if I shift into them I am rubbing the big ring with the chain. When in the big ring I find that I probably shouldn't use as much of the cassette as I do because my chain is prettry angled but cross chaining a bit I can get a gear that gets me about 14 mph. I only use this gear if I know I will be going faster soon...if I am going to spend much time there or the climb is longer and or steeper ahead I will drop to the small ring. It is a chain and does take a little getting used to but I think I am pretty comfortable with the gears now. There is plenty on both the low and high ends of the range and I think the double will make me faster since I will be in the big ring and pushing a bit more over rollers so as not to cross chain too much. Avg speed for 50.46 miles today was 16.5 mph with some good climbing, a few stop lights, and signs and one breif rest stop to refill my bottles and chew a Powerbar, that is up a bit from my last long ride.

Plus it just looks better on the bike than a triple.

I've done exactly the same thing, went from a FSA Team Issue carbon triple with a 12-25 cassette to Ritchey WCS compact double crank with a 12-27 cassette on my KHS Flite 2000. I had it out today for my second ride since the change and I find that I can cruise just a fast as I could in the big ring on the triple and that I can take hills at a higher speed than I could before by staying in the big ring on the Ritchey - about a 2 mph increase, but none of the hills I rode today were long ones, so staying in the big ring (50) wasn't an issue. The ride was 27 miles on my favorite route with a mix of flats and hills (about 75% flats) and I averaged 20.05 mph which is my second best time this year. I like the Ritchey WCS compact crank, and I agree that it does look good, especially since I have WCS seat post, stem and bars, which kind of ties everything together.

Does Campy have a 12-27? I ended up with 13-26 because it was that or 13-29. I would have gone 12-27 myself if it was available. I guess anything is possible though.

I've never actually checked but if there's no 12-27 campy then there's another reason I liked going compact.

I put 405 miles on my compact during Ride the Rockies has well has about a 2 weeks worth of training on it before the ride (I had just finised a component upgrade). It was very good for climbing and I didn't spin out at 50-12. I passed many people going up the grand mesa who had a double and some very large cassettes.

I think zacster is right... Campy does have a 13-29 that would *really* help with the low end. I don't think they have a 12-27 which, as you said, wouldn't have the nice .close spacing.

nope.. 12-25, 13-26, 13-29.. no 12-27 like Shimano. I love my compact double and don't regret going with it in the least. I'm running an 11-23 but considered a 12-25.

For the steeper climbs I may consider bumping up to the 12-25 but for now I think I just need to tune up the engine.

Ditto... I could have copped out and gotten the 12-25 but I figured getting the 11-23 would perhaps help with the engine tune-up

But with Campa, you can build your own from loose cogs. Easiest route is to change the low end of an existing cassette. But there is no 27 available, just 26 and 29. You could probably also add a 9s 28 at the top if that is what you wanted.

Or you can just get a Miche cassette, which are built from loose cogs and you can specify what cogs you want.

You can always run a 50/36. (I have this now)

53/39 is good too. (got one of these I had left over on the other bike)

They both have their pluses and minuses and I would be happy to use either one honestly.

The compact does give you more possibilities than the 53/39 and that's why I think it is cool.

Right now I'm planning on building a fixed gear (although to ride on flat ground recovery days) and even a 53/39 w/ 11-23 looks plush compared to this fixie.

fixies are fun

Would have to agree.

I use the fixie for my everyday commute to work.

THese are pretty nice.....

Off topic I know, but I can bring it back on topic by saying I think it will be cool to use a 110 BCD Gossamer Mega Exo with a Rocket ring for a fixie. Here is an example of a such a compact crank being used in a Fixed gear application https://www.bikeforums.net/showpost.p...3&postcount=26

holy crap that bike is so ridiculously sexy... and I love the wheels.. wow

The 50 to 53 top end difference is hardly noteable. From Sheldons gear calculator:

53 X 11 @ 120RPM (700x23 wheels, 172.5 crank)= 45.2MPH

While

50 X 11 @ 120RPM (700x23 wheels, 172.5 crank)= 42.6MPH

-Not accounting for wind resistance. The bottom end will be much better (more noticeable), even if crossed over only up to say 3 from your biggest rear cog.

I've got the 50-34 FSA mega exo SLK compact on my bike now, too. I thought it was great as I wasn't winded on my way up the San Gabriel Mountains northeast of Los Angeles.

Since I live in the Foothills, I need such a crank. The best part about it though, was that I was much more willing to tackle uphill climbs, which are still a little difficult. With the compact, though, I want to attack the mountains, and I don't have to worry about busting my knees. A bike shop owner suggested I get the compact. He was right, and I thank him for the advice.