What is the advantage of reprograming BMW x5's gearbox?

The dealer will tell you that it helps overcome the "lurching" that the 2000 - 2007 X5 with the ZF 6 Speed Auto suffers from, but good luck with it - Ours had a software download 3 times and it's still crap, uncomfortable and sometimes dangerous @ junctions and roundabouts with gearchanges. Check out www.thelurch.com