Actually, after giving it some thought, I decided not to buy the 24mm TS-E II (82mm filter size), which will free me from the burden of replacing my 77mm Hoya filter set (I have 1, 2, 3, 6, 9 stop filters, so you can see I'm already heavily invested). Instead of a tilt-shift lens, I'm going to experiment with focus stacking, which may turn out to be a whole lot better anyway. If it turns out that 90% of my shots could be done with focus stacking instead of T/S, then I've proven my point.
I'm still not convinced that the pervasive love affair with T/S lenses is merited. I need proof before I buy.