I think CFTBL is awesome, I really enjoyed it while I had it. DM I've owned 3 times, love the flow and the "bang for the buck". BSD is darker but has that really cool mist multiball, but I didn't keep mine for very long. RBION I've had for nearly 2 years now, it is a very deep and fun game which I will recommend highly. I've never played Tommy.
I wouldn't sweat over it, just get the one you are most interested in today and play the heck out of it. Sell it if/when you tire of it and buy a different one. That's the pinball hobby! You will tire of every machine eventually anyways!
-Brannon