I own a Trek Verve (an older model, with a suspension fork) and I have tested a Specialized Roll as well. The Roll has a significantly different feel to me than the Verve. Both are great bikes, but if you ride both, I suspect you'll quickly zero in on one versus the other. Having grown up with rim brakes, and having used them all my life, I have since come to prefer disc brakes, and the Roll offers them. The Verve does not (except if you buy the electric version of the Verve). Rim brakes are generally just as powerful, but I like the feel and consistency of disc brakes, especially nice ones (you can certainly find cheap discs on department store bikes).

Besides the brakes, the biggest difference between them is the handlebar. The Roll has a super high-rise bar (similar to a BMX handlebar) that puts your hands way up above the level of the saddle. To be fair, you could swap to a lower rise bar on the Roll if the high rise is bothersome, or you could swap to a high rise bar on the Verve, if you'd prefer higher hands. I say that to suggest that either bike could be setup pretty closely to the other one, so if you find you like one bike shop better than the other, or the colors of one bike better than the other, you can definitely customize either one to really dial-in the fit.

Enjoy the ride!