The difference between the "dotty" humbuckers and the "plate" ones is that the "plate" ones have covers over them. They're still pretty much the same on the inside... (I think, haven'r really gutted one to see :P) But as for the difference in humbuckers the Jackson is likely to have Jackson humbuckers or Seymour Duncans in it, while the F-250 has a set of EMG-HZs (Either HZ4s or HZ1s...). From what I've heard about the EMG-HZs, the only good ones are the HZ4s. Seymour Duncans have a nice sound, or the ones I played on did.

Both Jackson and ESPs (LTD) are nice brands of guitar, so whichever you pick is going to be good. The Jackson is likely going to have the better sound though if its a Warrior XT. If not then I'd swing for the F-250. But that's just what I'd do...