Decal faith restored.

Having posted recently about decaling my Airfix Lanc I have just had an enjoyable evening decaling my Hasegawa F15. What a difference - the Airfix decals were overly thin, resisted movement when on the model, curled on themselves and generally were difficult. By contrast the Hasegawa decals have behaved perfectly even when required to be wrapped around the wing tips. Is there a reason for this difference as surely Airfix have made decals for long enough to have the correct formula. Are there generally decals to be avoided to prevent tears! Thoughts welcome.