If you get 10 replies no two will be the same since this is an opinion question, and since everyone has a different opinion..........
I would say the main "Problem" with external recessed lights is that of water ingress. This can be caused by using a cheap fitting, bad installation, damage (Accidental or otherwise) or a combination.
If you are going for the 12v option I suggested in your last post then there are quite a few options of sealed LED illuminated light fittings. These usually have a "fly lead" that you would need to pass through the wall and make connections in a weatherproof enclosure.
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