I'm in the process of building a P-51D Mustang display for this years IPMS R5 convention here in the Twin Cities. I'm building 8 1/48 D Mustangs of all manufacturers, and IMHO here are the ones I'm building/built in ranking from best to worst.
1. Tamiya "Great kit, no problems"
2. Hasegawa "Again, Great kit, I just don't like Hasegawa's brittle plastic"
3. Arii / Otaki / Airfix "Cheap, needs some filler, nice kit though"
4. Fujimi "Okay kit, needs filler"
5. Monogram "Open gunbay detail"
6. Hawk / Testors "Nice kit, no cockpit, easy build, needs filler"
7. Revell / Nichimo "Canopy mis-shapen, needs filler"
8. Hobbycraft / Idea "This kit is a knock-off of the Fujimi kit, with raised lines"