IMO you would be better off going with LPS 3, I just did mine last week. I did lots of reading on FF v. LPS 3 and found a couple of tests people did with similar results. Here is one I bookmarked:
Protective spray??? - Page 2
The main issue for me is that FF will wash off, LPS 3 will not. The crap they use on the Maine roads is so nasty I hit the car wash weekly, FF would not last long on my truck. LPS 3 (according to what I've read) should last 2-3 years. I got mine on eBay from a vendor called Zoro.
If you go with LPS 3 make sure the product is warm when applied, do in a heated garage with some ventilation and wear gloves. It's basically a wax coating (when dry) and cleanup requires a solvent.
Good luck!