I have the 5.4L V8... that said I really didn't see any seat of the pants difference with the FIPK on my truck. I really didn't like the fit either but all the after market intakes for my truck install the same way buy using the stock Mass Air in between the Filter and the tube. I would probably buy it again though...
Now as far as destroying the MAS (MAF) any oiled filter can do this, kind of. What happens is a film is built up on the element... all you have to do is clean it and you'll be fine. On my Ranger I cleaned mine 2 times (I think), probably not needed but I did it anyway.
Just don't over oil the filter and you will be fine.
Here is the
LINK to cleaning the Ranger MAF... or just do a search on
Google for "MAF cleaning" and you will gets lots of info.
Hope all this helps...