I've gone back and forth on this one, originally saying the 268 "feels" like the "best" road frame VeloBuild offers. It's certainly better than the 168, but I'd argue both the 268 and 177 have their respective places on the market.
VB-268
-Not offering a 15-20mm setback setpost is almost a deal breaker. But I'm probably in the minority here. You bike fit may vary.
-If you plan on ever running 32c tires then this is your only option. The 177 can just barely fit 30mm measured at the rim. Only on dry roads. With that said, I pretty much exclusively 28c on rims that stretch out to around 30.
-The Mavic thru axle system is easy to use once you get the hang of it.
VB-177
-Personally speaking this frame looks better to my eyes. Not as aero looking of course, but classic proportions. And the design will most certainly age better over time.
-27.2 seatpost = 3rd party aftermarket support.
-I find the geometry overall worked much better for myself over the 268.
Performance wise (stiffness, speed, etc) they are about the same, with the 177 being slightly better over bad pavement. Wheels and rider position affect riding dynamics more than anything else. Both are a nightmare to route cables if you plan on using a mechanical groupset. Especially the FD. It's not impossible but will take some time to finesse properly.
If you need the option of 32c tires but don't require a 15-20mm setback seatpost, the 268 is probably the better option.
