My last daily driver - a 2003 Mercury Sable with the Duratec 3.0 liter V6 - Spec'd the FL820s filter, and that's all I put on it. Never once had a problem. Considering they can be bought at almost any auto parts store, or big box store, for about $4, they're hard to beat for the price.
Yes, a Fram Ultra is technically a better filter in terms of filtration efficiency, mileage rating, etc.. and has wire backing, but it's not necessarily going to be better for you, depending on how many miles you generally put on a filter.
If you're running a 5k OCI/FCI, stick with the Motorcraft. They're frankly very hard to beat, for the price.