I've stayed at Fairfield, Paradise Pier and Grand Californian. I have yet to stay at DL Hotel, maybe 2005. Anyway, unless you can swing the Grand Californian, I'd say stick with the Fairfield. The GC is my favorite hotel, but I can't justify the extra expence.
You will have about the same walk to the front gates from the Fairfield as you would from PPH and DLH. The only Disney hotel that has a closer walk than the offsite hotels is GC.
The amenities at FF and PPH are comparable, you just won't get Mickey soap. Your room at the FF may be a bit smaller than PPH, but since its really just a place to sleep, you won't really notice. It's not like WDW where staying on property is pretty much a necessity. There is only 1 perk that you get that is fairly new, and that is an early entry to Toontown. This might be nice, but not worth the extra expence of staying onsite.
For me staying on property is nice once in a while, but not a necessity. I'd much rather stay at an offsite hotel and use the saved money on character meals, lunch/dinner at the Blue Bayou or the Fantasmic preferred seating.
My favorite offsite hotel is the Carousel Inn and Suites. With
AAA or Entertainment discounts, I've gotten a room with 2 queens for $59 or a 2 room suite for $99. Its a few hotels up from FF, and closer to the entrance to DL.