Wholeheartedly agree, "Minder" was a great show, and Arthur Daley a great character.
If anything, I think the one thing that became a bit long in the tooth, with time, was the relation between the two main characters, who shared star "duties" in the first 7 series.
Strained relations are the base of most sitcoms, but there is a point, to me at least, where the strain becomes stronger than the "believability" of such situation, so to speak, and Terry McCann had passed that point quite a while before Dennis Waterman quit the series himself, it seems to me...
BTW, don't know about you, but I quite liked the 3 series of Minder sans-Waterman... nothing against him, on the contrary, he might be one of the classic one-role-only actors, but what he does he does very well, it's Terry McCann I couldn't "believe" much anymore, as I was saying, and the new "situation" did fit better, to me, with more room to move for George Cole as the sole star of the show, and a new and more "modern" minder who, being Arthur's nephew, was better suited to be stuck with him indefinitely...
Not as good as the early series with Waterman, probably, but better than the later ones, with the exception of the excellent special "Minder on the Orient Express", a lovely spoof of Agatha Christie in Arthur Daley's sauce

A funny anecdote, which George Cole often relates himself, is that, when he was a young lad, his adoptive father and mentor, the great Alastair Sim, had tried for a long time to get George rid of his cockney accent, to become a more versatile actor, with some success, and after all that effort, the roles for which George Cole will be remembered most are those of the cockney spiv Flash Harry in the St. Trinian's movies and, indeed, Arfur Daley
