The weather's crap - windy and wet so I've been playing around with speakers. I'm not sure the dog is impressed!
The Avalons (NP 2.0) have been unused for years and I've been tidying them up for sale, so a comparison with the LS50s had to be done, powered by the SuperNait2/HCDR. Size aside, the LS50s do hold their heads up very well in terms of a biggish sound with quite deep and well-resolved bass, while the Avalons do definitely add accuracy in the lower registers. The Avalons' ceramic tweeter is not as sweet as the KEFs' and of course their dispersion characteristics are quite different, but they are both 'modern' in terms of overall character, eg clean and dynamic. I remember the Avalons as being notably musical, and they still are, but they are quite efficient and I can't stoke them up properly while neighbours are at home today! They probably need a bit of use after years stored upstairs.
The Avalons are still quite nice looking things, with pair matched veneering on both cabinets which was and still is unusual for relatively affordable speakers. They are unusually compact for an American speaker too, and very sensibly designed to be heard with the grilles on (they sound unbalanced and 'wrong' with the grilles removed). I still like them, but the LS50s are probably a better speaker for a small space like mine.