...if you already know all this, I apologize, but "generally" the bigger you go in tyre size, the heavier your rotating weight gets. So there's a point at which the comfort and stability provided by a larger, fatter tyre starts to act a cross purposes to riding pleasure. For me, that's usually in the 700x28-32 range as a practical maximum, and I do have some wheels I built with newer lightweight rims that roll OK with Panaracer 27x1 1/4 tyres on them.
I have my most pleasing results with tyres like the old Rivendell Ruffy Tuffy, or some of the newer versions of them (also made by Panaracer). They're relatively puncture resistant, capable of holding high pressures with a modern hook bead rim, and mostly average in the 28-32 mm widths I prefer. they seem to do pretty well in the rolling resistance department. Anyway, this has been my experience after a lot of experimentation.