When I raced at the track I went from 1,2,D3. Actully D3 for me at least shifts at 5900. and I can shift at 6500-6600 by myself. Brake-gas really does help your times. I held it tell 2k and ran 16.6 consistantly and tryed to do 1500 and random numbers like that and ran high 16's. I think 1,2,d3 is quicker but you have to shift in quick and dont take your time. every one-hundredth of a second counts!

Also, if you are say racing at a low speed, depends on speed. But if say you have enough room to put it in 1st at around 4k let it rip and you will feel it a lot better then flooring it in D3 and having the deley of it downshifting automatically. Drive safe and learn to drive first.