There isn't too much you can say that is negative about this bike or about Guru, the company that makes it. Guru is like the Dell of bike companies. They build their rides one customer at a time and the Crono is their flagship. This is the bike 2006 Kona runner up Desiree Ficker rode. This is the bike I thought I was going to walk out of the store with when I started looking for a new tri bike. But that didn't happen.
The hard thing about reviewing a bike like this is no matter what I say about my experience testing this bike, I will always have to use the disclaimer, "This may not be your experience." The reason for this is the bike is made custom unless you buy a used one off eBay or take a floor model from a local bike shop. The folks at Jack and Adam's stressed this point throughout my tests on this and every Guru I tried.
What I liked about the Crono was its unique styling. The bike looks like you could take it out for a ride then hang it in your living room like a museum piece. It is both cool and sophisticated looking at the same time. In my test this bike was fast and solid through corners without sacrificing any agility when changing gears or directions. On flat sections of road, the bike just moves and moves fast. As far as road shock, there was literally none. This bike was like riding a sofa. So if you are one who needs a softer ride and you have about $4500 to spend (for Ultegra) then this is a bike to consider. Also keep in mind the 10 year warranty. Ten years is really good, especially for carbon frames. But lifetime is better.
What I didn't like about the bike I tested was the same cushy feel that made me feel as though I was riding on air on the flats completely left me feeling as though I was riding through quicksand when it came to climbs. As the friend who was with me that day put it as he watched me on one hill after another, "Your legs were a blur. But you weren't going anywhere. I kept having to hit my brakes to keep from running you over..." Ok that is a bad thing. My buddy is about 6'2" and weighs close to 230 lbs. I am 5'8" and 159 lbs. You get the picture.
To put this into further perspective, a couple of days later I was on my road bike sailing up the same climb. I was able to bridge up to local pro triathlete Andrea Fisher who was on her tri bike. Andrea is a human specimen to put it mildly, about 6' and at least 165 lbs of solid muscle. My point here is once we hit the flats again she was gone and I couldn't stay with her. But on every small rise I could gain ground. This experience got me thinking about the Crono. The wheelbase on this bike was one of the shortest I tested and it was the least effective climber in the bunch. From my experience on these bikes the shorter wheelbase helps get you in a steeper position and further forward over the cranks. This is great for triathlons because it saves your quads for running. But you pay for this positioning on climbs because you don't get the same angle to apply leverage to the cranks by using your seat as counter-leverage. On a flat or gently rolling course this won't hurt you much. And if you are a larger rider able to produce more power on the flats you get this time back and more anyway just like Andrea did to me that morning. But if you are an efficient climber, one who can sustain high speeds going uphill, this bike could cost you unless the folks at Guru can address that concern specifically when your bike is being built.
All in all the Crono is an excellent bike. It is aero and fast and silky smooth. And it is one of the best looking bikes I've ever seen. The difference with this bike is probably how well you can communicate the specifics of your riding style to the folks at Guru so that the bike can be built to emphasize your riding strengths and not take away from them.