To quote the DH, "Buy Cheap...Buy Twice". I was also in love with spin class so I got the DH to go with me. He loved it even more than I did...so much so that he went out and bought a fancy Trek Madone. Once he started riding, he refused to go back to spin because it didn't compare to the feeling you get on that road bike. He talked me into getting one of those fancy carbon bikes (I got an Orbea) and I fell in love. Now, I can't stand the thought of going to spin class when I could be out on the road. We ended up cancelling our gym membership (saving us over $1,000/yr) and buying a trainer for the times we couldn't take the bike out.

My recommendation...buy the bike that feels best. Worst case scenario...you decide you don't like it (which I highly doubt) and you should have no problem finding someone to take it off your hands at a slightly discounted price.