The Warden is so much shorter than the others that I find it hard to compare with Barchester Towers or The Last Chronicle, etc. I think Framley Parsonage is probably my favorite of the Barsetshire novels, simple because the character of Mr. Crawley is so fascinating. Apparently he was patterned largely on Trollope's own unfortunate father.
Does your husband brook any criticism of the later novels (e.g. The Way We Live Now?) Surely he admits that that awful novel about the British colony that adopted euthanasia (The Fixed Period) is pretty bad?