There are probably a lot of threads about stronglight pulsion cranks,good or bad so i thought i'd share my experience so it may help.
I had creaking after about 100 miles ,some in the wet. I checked pedals,cranks and found it to be the stronglight twister bb that they recommend you fit. I bought an fsa titanium bb and its been fine ever since.
I paid about £87 for the twister bb and the fsa was arond £67.