In my opinion, if you're already and experienced driver, then you don't need a lot of study time. I read through all the questions in the DSA book once (it took me three days... so boring!), and highlighted ones that I could possibly make a mistake on. I reviewed those the morning of the exam, and got a 35/35. Woohoo!
The hazard perception, however... definitely practice that! There's a £10 CD-ROM with 125 different hazard perception clips on it, and you can review the clips after you've finished to see where you've clicked, and how you scored. First I was clicking too late, then too early, and finally just right! I thought the clips on the actual exam were much easier than the ones on the CD-ROM, so it was all OK in the end.
