I've just got this kit from Hannants on sale,
It is one of the best kits I have ever seen in terms of finesse and accuracy.
I obtained all the available Vector sets for it, and they are all worthwhile:
The one-piece Vector cowl of the exterior set (in itself a big bonus of simplicity) has thicker cowl lips edges than the kit's plastic cowl, and this is a major improvement. I did have to heat it in hot water to squeeze it very slightly into a more perfect round... Another big bonus of this resin cowl is the much more refined and accurate valve-clearing bumps.
The Vector resin canopy is even clearer than the very good kit clear part for this remarkably huge canopy (it looks like a 1/32 scale canopy!), and they elliminate a significant and unfixable mould flaw in one corner of the kit's plastic glass... The Vector resin clear parts also slightly correct some of the side window proportions very slightly.
I don't know how much of the Vector cockpit set I will use, but the resin seat is definitely worth the investment by itself.
The only downside was that the ailerons/flaps on the exterior resin set were warped in a curve, but the cowl alone makes it worth getting the exterior set, as the plastic ailerons are excellent anyway...
With the kit and resin combined, I feel this is one of the most accurate kits I have seen: The finesse of the fabric effect on the wings, and especially the sharpness of the trailing edges and wingtips is second to none, and ahead of most: You can gauge this by the finesse of the depiction of the "notch" in the wing that is over the pilot's canopy: This feature has its edges much more heavily bevelled and sharp than in any other kit I have seen with this same "high wing" feature, and it creates an outstanding "true to life" effect that shows just how much this kit is a cut above...
Don't be swayed away, as I was, by the subject's confidential nature... Even on sale at 12 Pounds, with all the Vector resin it does add up to a high price: It is worth every penny, and is probably the most refined model in my stash... It will now be hard to put it off for more glamorous subjects...
Gaston