I have an X:
I've had a mixed history with flat and drop bars. I'd had flat-bar disc braked hybrids prior to my first drop bar bike in 2010 (a Trek 1.1), but got on well with a Trek and upgraded quickly to a custom Kinesis Decade Convert2 build. However, while I liked the drops, I just couldn't be doing with cruddy road calliper brakes and I'm not man enough for 25T rear cassettes!
Enter the X. I bought the frame in January 2012 and transferred the majority of parts across from the Convert2.
The drivetrain is a 9-speed mix of Tiagra 4500 shifters, 105 5700 34/50T chainset, SLX / 105 mechs, XT chain and SLX 11-32 cassette. Wheels are XT M756 hubs and Conti GP 4 Season 28c tyres on Mavic TN719 rims. Brakes are BB5s and finishing is Easton EA50. It weighs 23 lbs and, although I'm tempted, I think I've reached point of diminishing returns in terms of upgrades.
The finish of the frame is great and, despite an iffy road.cc review (balanced by lots of positive ones), I've found it rides perfectly for my needs as a workhorse and tourer with occasional gravel roads thrown in. It's worth noting that I've had trouble fitting a pannier rack due to the positioning of the BB5 calliper - the pannier mounts only work without discs and I can't even make my Tubus QR axle adapter fit to get around this. You shouldn't have this problem with the Roadrat.
The best and worst thing about the bike is that it has accidentally become my main bike. It's so versatile that I'm doing ten hours on it for every hour I spend on my Cotic Soul (decked out with XT/R, Hope, Thomson, Fox forks etc). It seems a bit perverse to be spending most of my time on a workhorse when I have my nice kit in the shed.
Despite this, the X just works so well even wearing its humble kit. It also looks very good in real life - I get a lot of compliments. There's a lot to be said for having one flat and one drop barred bike in your life.
The Roadrat did come in long and short versions for flats and drops respectively, although the short version was dropped when the X arrived. I hear the Cy doesn't like drop bars much and you won't be surprised to hear that the X rides very much like a MTB'ers roadie.
You'll see that Cotic only have the 58cm frame left and I hear a whisper than the X will be replaced with something else. I was thinking of a Roadrat in replacement, but if Cotic do a "Y" with proper pannier mounts then I will definitely go for that.