Consider your leg length and how that might affect your ability to vary the seat position which in turn affects many other aspects of your fit.
If you don't feel significantly better on one vs the other then it's probably not going to matter much. I'd however want to do an actual ride of a mile or so on both. That way I can figure out which might give me more or less confidence when maneuvering fast turns and slow turns. As well did I feel like I was going over the handle bars on one when I braked hard, particularly when going downhill?
A fairly wide range of frames can be set up to fit your body, IMO. So don't let the 1-1/2 inches of difference between the 58 and 61 cm frame bother you too much. Providing of course that your leg length doesn't suggest that you should favor smaller or bigger. Even with that some might ask "how 'bout your reach?" That might throw everything back the opposite way.
So if your gut instincts and any insight the people at the shop give you as to which way to go, then go for it. Getting bogged down in the mathematics of the perfect fit will not have you on a bike very quick.