I doubt you'll like a 1.5 any better than you did the 2.0 you owned for two weeks. It should fit your x-seam (45", IIRC), but your BB will be low unless you can get hold of a chainstay extender. The low BB may give you problems with the edge of the seat where it hits your legs, as well as being less aero. The top of the seat back might be uncomfortable between your shoulders, since you're fairly tall. Recumbutt is also a possibility with the more-upright seat angle.
I loved my Silvio 1.5. Great bike. But certainly not right for everyone.I would have guessed exactly the opposite as your first part.