The wing could be cleaned up it doesnt need all that crap hanging off the thing could never be described as STOL
couple of considerations ...
(a) for civil, there is no such thing as serious STOL .. the aircraft still has to meet the normal design standards .. military is a different matter .. so those who have flown the civil variant haven't seen its STOL capability. One needs to keep in mind that real STOL operations involve a moderately increased risk of mishap, especially if the noise stops ... I have been in the back for some serious performance landing trials .. and the numbers are more than respectable .. while being more than a tad terrified .. OK it was good fun... but definitely not your average Chieftain landing.
(b) the lateral control system is comparatively sophisticated .. not many comparable birds around which can stooge about at Nomad speeds ...