ARs are great! I prefer the generation before the 18, i.e. the 3a, 4, 6, etc as they had a much nicer real veneer cabs (18 is a vinyl wrap IIRC) and the wheat grilles look cool in a ‘mid-century modern’ way. A friend has a pair of AR 6 in his kitchen driven by a wood case A21 and they sound lovely, as ARs do. They are obviously a bookshelf/wall-proximity speaker so become unbalanced when pulled out into the room, but they are really good speakers. Ed Vilchur was one of the great audio designers. An amazing legacy.
PS Rob got one of the best sounds at Scalford one year with one of the smaller ‘70s Marantz and I think a pair of AR 4s. They really work and show just how good a sealed-box speaker with an 8” paper bass and simple tweeter can actually sound. Surprisingly big, warm and punchy without any harshness. Rob had rebuilt to amp and replaced the foam driver surrounds as one has to with these speakers.