Friedrich August was generally regarded as a kind and genial man who had a good sense of humour, it was not just a matter of how he looked in photographs (though those in fact express something about his character, the appalling Georg actually looks rather unpleasant in photographs).
There is nothing more difficult than judging the state of marital relationships, and the causes of their failure, from second-hand reports. My view, for what it is worth, is that Friedrich August would have made a very reliable husband for the sort of woman who would have appreciated his qualities and enjoyed a quiet domestic life, and Luise was not that sort of woman. She was flighty (and, I suspect, highly-sexed and self-indulgent) and may well have found him dull. He was certainly an excellent and much-loved father, and in difficult circumstances too. As far as I know Albert got on very well with Luise. I am more inclined to feel sorry for Friedrich August than for Luise, who went to make a mess of her next marriage; if he had found the right wife he might have have had as happy a marriage as Ludwig III of Bavaria (another 'boring' man).
