You can change them at the command line if you wish.
eg
defaults write com.binaryage.TotalSpaces2 transitionSpeed -float 115
For extra information - the slider goes to 110 (for historical reasons). The duration of the transition is calculated as follows:
(100 - transitionSpeed) / 160 + 0.2 seconds
Faster transition speeds do not necessarily work that well though, ymmv.