I would have no problem with a player in my group (if I had one (sadface)) went with the double-triple digit speed modification.
And it would be even more fun if they took movement power on it too.
And hilarious if they FORGOT to add the Guard power.
Hmm, troll, 53 meters per turn equals 17,66 meters a second or 1059,6 meters a minute or 63576 meters an hour - or 63,576 KM/H
Here's a benchmark on human reaction time:
http://www.humanbenchmark.com/tests/reactiontime/stats.phpLets assume that the Troll has wired reflexes 2 so he has an average reaction time TWICE of a normal human, about 100 Milliseconds.
This means that he reacts within 1/10 of a second, that gives him 0,9 seconds to change direction in the case of a risk of collision. In 0,1 seconds he travels 1,766 so the minimum movement before he reacts he would move 19,426 meters.
Unfortunately he has only 2 actions in a combat turn which means ONE action is 1,5 seconds so he would move 28,256 meters in his first action before he can actually begin the next one - If we assume he spotted the imminent collision at the end of the first pass.
Its not always good to be fast and SR4 makes movement even more complicated.
If we assume that the troll is a vehicle, how badly would the collision rules damage him?