I have to agree with Johnf3 it wasn't about the power increase as much for the ease of maintenance.Anyone who has a 950 SE and are riding them in the conditions they were designed for I imagine like me were sick of pulling the bloody tank off and cleaning the useless pre cleaner after every dusty ride.
As long as you take your time fitting it, mine had to have a slight die grind on the under side of the base plate (no big deal)
to get it sitting flat and snug.Do yourself a favour and get a head to wind jetting kit and SAS blanking plates RC8 velocity stacks as well as a couple of packs of filter skins(6) is good I have two on all the time.
The best part is when you get home from a dirty ride just pull the seat off reach in peel the top skin off put a freshly oiled skin on and your good to go I reckon I could do it in about 30 seconds seat off seat on and if you need to get main foam filter out you can do that too without pulling the tank off.But when putting the filter dome back in making sure the hinged side is clipped under properly and it sort of clicks over the dusses clips to seat and seal properly if you install this filter yourself you will understand better how it goes together and then will be able to do it all with the tank on.
Power increase it dramatic as well mine hasn't been on the dyno since and there is no need the fuelling is spot on no flat spots no more popping and the thing wheelies off the throttle in 3rd gear!
Finally I believe if this filter is installed correctly you won't have any sealing problems and will turn your 950 or 990 into a great dirt bike money well spent I say Cheers Emu