The tires on the Kilo WT are 700x32c road tires, which are a lot wider than the Kilo TT (700x23c), but not nearly as wide as MTB and have a smooth road tread. I have a Kilo WT, and it's a great bike. It also has better hubs than the regular Kilo TT with sealed cartridge bearings, and you have to pay another $50 to get them on the Kilo TT Pro.

Another advantage of the Kilo WT over the Kilo TT is that it has hooded brake levers, which gives you another hand position for increased comfort. You also have access to the brake levers w/o having to move your hands when riding on the drops, which is safer.