Disc brakes aren't going away. Accept that now. Hold onto your opinions, your convictions, your purist's zeal for short pull rim brakes and 19mm tires. But accept that disc brakes are the future.
I've been experimenting with them for over a year, when I hopped aboard a BMC GF02 Disc. I dug it. All the stopping power, and in all conditions, makes confidence flow like sweat. Rip the descent off Smokey Hollow. Take a chance on the gravel turns at Lowell 50. It's a consistency that makes a lot of sense for any rider.
Salsa is a company that seems to be consistently 2 years ahead of the game. Their dedicated road bike, with slightly more relaxed and forgiving geometry, has been disc since the technology was first introduced and became available in the industry. They've stuck with it, even on their highest end offering, the Colossal Ti.
This bike starts and ends with the most forgiving and responsive material out there. I've ridden carbon, aluminum, steel, and nearly every variation of each one. My first ten miles on Ti were impressive; first a 500 foot ascent of M-72, followed by a dash across chip seal and a touch of gravel. It's just smooth, without feeling like a noodle.
The rest of the bike is spec'd to the quality you'd expect to see draped over a titanium frame. Ultegra everywhere, plus a Ti seat post and Thompson stem. My favorite pick is the HED Belgium+ rims. They're the same ones I used on my custom SSCX wheels. They are 25mm rims, which made the tire stand wide on the rim and smooth out the ride like crazy. They are also 32 hole, and while maybe overkill for normal road riding, for gravel (which this bike will see plenty of) they are the bomb-proof set up I always look for.
The only changes I made were partially aesthetic. The white bar tape was already brown after a spin in the parking lot. I'm no bike mechanic, but I get into the pits of the service area enough to know that white tape doesn't stay white. Black Lizardskins DSP 2.5 took its place. And of course, I put my favorite Arione saddle on. There's an Arione on most of my bikes, and this one gets the new R7 model.
I did test and confirm Salsa's claim of 30mm tire clearance. I tried to slide in my Michelin Muds, which sit almost 34mm wide, and while they had room laterally, they just barely kissed the underside of the fork. I think a wide 30 tire with a big of chevron will be enough for most of my gravel racing, and if that isn't enough, I'll use a different bike, like nearly everyone.
With cages and pedals, the Colossal came in at just over 19 pounds, not shabby at all for a disc road bike with overbuilt wheels and no dramatic attempt at weight savings.