OleBoy, it depends on what you are looking for.
The LF1 version covers the later model WWII D models, while the LF2 package covers the earlier model WWII D models, so with the old style cockpit and the smaller tail.
The later then & now packages each cover one particular Mustang, showing them in WWII and present form.
The restored packages contain different modern day warbirds. So it is up to you, they cover nearly all Mustangs as far as I can see.
As for the comparison with A2A, I have both, and love both. I have also done lots of paints for both. Personally, I think the WBS looks better, and gives you lots of different versions (early and late D's, Iwo Jima (A2A too), mirrors, no mirrors, exhaust shrouds or not, cameras (any chance of a paintkit for that, John?), but I do miss accusim, which gives the A2A bird far more character to fly. Now if we could combine the looks and variety with accusim....