No LBS, fitter, or test-drive can tell you how a bike will feel.

You buy a bike that is close to your size, do a quick fit, ride it for 100 miles, maybe 250 miles, and then start adjusting the fit.

How long had you been road-biking on a aggressive road bike like the Tarmac before buying this one? The Tarmac geometry is for racing, if you wanted a more upright bike, and a more upright neck, you should have gotten a Roubaix.