Martin has commented elsewhere that he may well detune the 31 a little when he has time as it's clearly rather too lively at speed (at the moment he's busy frying other fish...err, slugs
). Meanwhile if you want to have a play yourself and can't quite follow the acceleration figures in the train.dat file, try downloading the Train Editor from Trainsimcentral. Beware that saving changes from the acceleration dialog on this program enforces a minimum of 1.0 on the final figure in each line of acceleration data. Martin set this value to 0.9 in the higher notches to keep the loco going at higher speeds - increasing the number slightly will tame the loco but you'll need to edit Train.dat with Notepad or similar if you want to use values below 1.0.
BTW, I don't know whether Bill will confirm this, but Martin's take on the name 'Ped' was that drivers noticed how slow the load regulator is to run up on these machines, which makes starting away a bit slow. This is reproduced on the model - watch the current rising slowly as you notch away - and has the advantage that it makes the thing pretty well impossible to overload!