Just to clarify, as others posted, the 03-06 Lxi was one boat, the 07-11 Lxi was a completely new boat, and the 12-up TXi was another large change. (current generation) The 03-06 Lxi was an outgrowth of the Response and Response LX, using the same Diamond hull and just making it wider and longer. Great all-around boat. The '07-11 greatly improved the ride quality in chop, less (almost no) water over the bow, and good shortline ski wake. Long line length ski wake was debatably not as good. '12-up TXi fixed all that, by keeping the good ride and little bow attitude change for a dry ride, and improved the hull to give all skiers a great slalom wake. Noticeable change. Other item paid attention to was the '12-up is very much a driver's boat, with better windshield, dash and driver ergonomics.
The '03-'06 LXI was the best longline barefoot table if using for multidiscipline, but the TXi ('12-up) is the best slalom of the line up.
On a side note, the Response (closed bow) is still arguably one of the great buoy tractors for course-only use, such as private lakes.
pb