1. Try them on, one on each foot at the same time. See which you prefer. For me it felt like the FTs were low ankle boots. The dalbellos feel like they have more support. But that's just me.
2. Consider this for a sec. A lot of full tilts have plastic buckles. PLASTIC? On a ^$600 boot? The dalbellos have metal ones. The Full Tilt plastic, to the best of my knowledge, is a lot thinner than the dalbello plastic (in the lower shell). This makes the FTs lighter but it also means they wont be able to be worked as much as the dalbellos. Also have a look at the crank strap on FTs. Its very thin and doesn't feel that great. The quality just isn't there. The crank straps on dalbellos are much tougher. I have the Il Moros with the ratchet crank which I think is the best feature ever put on a boot, but that's just my opinion.
Summary: In my opinion, FT is a success of marketing over design. I know I've just committed newschoolers suicide by questioning the choice of the Hon. Tom Wallisch but if you're going to be using your boots for more than just park then don't overlook the dalbellos.