For 10-15km, I don't think it'll matter so much. The advantages of a road bike are really only apparent if the commute is fairly long (like 30 mins +)
I've found commuting perfection in a cyclocross bike (Cannondale Cyclocross Ultra) which I bought secondhand.. I like it so much, if I could only have ONE bike, I'd choose it. With what I've done to it, it's probably fairly close to that Bad Boy you're talking about.
I used to ride a MTB equipped to be a commuter, nice drivetrain on it (XT) but heavy, crapped out shocks that didn't really have any travel anymore. I found it felt too heavy, the seating position too upright, and didn't handle all that great. The things I like about the 'cross bike are;
* it takes 700c wheels, but has extra clearance for wide tyres: so you can use thin roadie tyres for high speed, or use wider hybrid tyres for extra comfort and stability on unpaved/gravel tracks. I run 37mm hybrid tyres on it at the moment, but think they're a bit tooo wide.. gonna go for 28s or 32s next time I'm up for tyres.
* has a nice lock-out headshock with 1 inch of suspension travel, don't need any more than that when not going 'real' off road
* has all the mounting eyelets for a rear rack, and front and rear mudguards
* handles and sprints like a road bike, even when carrying a light load on the rack. I run a compact road drivetrain (34/50 crank, 12-26 cassette) which is a nice balance between flat road speed and low hill gearing when heavily packed.
* drop handlebars aren't as wide as flat bars, and you know exactly where the edges of the bars are.. makes for easier maneuvering around tight spots
It also happens to have a perfect little spot between the seat tube and seatstays where I can wedge in my light battery, fits perfect, as though it was meant to be there all along! 🙂
The only thing it doesn't have that my old MTB commuter had was a front disc brake, for 100% reliable braking in wet weather. But after dialing in the canti brakes well, it doesn't seem to be too much of an issue.
EDIT: just looked to see what a Giant CRX was. I reckon putting a rack (and mudguards if commuting in rain/wintertime) would make a great fast commuter bike.