Concerning the LS 430's hesitancy to downshift when throttle is applied, we found this is at least partly attributable to the artificially intelligent transmission learning the habit. I successfully 'trained' mine to downshift much more aggressively by using the stick to force a
5-4 or 5-3 downshift when I wanted a sharper moveout on part-throttle acceleration. After about a week I could see a difference, after about 2
1/2 weeks it had 'learned' the new response and now the car is really quite aggressive about quick part-throttle downshifts. It now drops down a gear or two almost instantly if I get into the throttle, even a relatively modest dab around town. The car's much more responsive for the 'training.'
If you try this, be sure that you *first* apply throttle and *then* force the downshift so the transmission logic gets it right.
-- Pete