Good stuff! The Airfix and Heller kits are both the same kit, as Airfix bought Heller, and of course a lot of interchange of kits occured. It's often possible to pick-up the Heller version for quite a bit less than the Airfix issue.
I can't really cooment on the Trumpeter kit, as I haven't seen their 'D' version, only the 'B', which certainly has some inaccuracies, as it seems most Trumpeter kits do, along with fit issues. As for the Airfix kit, overall it's pretty accurate, although it must be remembered that it dates from 1972, when the level of detail, then, was considered exceptional. By today's standards, it's somewhat simplified, and there are two, possibly three, areas I know of which need attention, but are very easily rectified by even the average modeller. The first is the instrument panel, which looks more like a P51B, but as most of this is hidden under the cowl and gun sight, it's no major deal. Second is the fit of the engine cowlings, which is less than perfect, as they were designed to be able to display the engine. Again, not a major issue and easily rectified with a little fiddling and sanding if required. The final point is the most serious, but once again easily corrected; the oleos are moulded at virtually full extension, so need shortening.
Other than that, it just needs some scratch-built detail in the wheel bays, which are bare, and perhaps some detailing here and there as desired. I've seen some stunning models produced from this kit, which is not bad at all considering its age.
Hope this helps.