The way I would look at the IRV vs. ITTR (top two runoff) debate: IRV advocates tout many advantages of IRV, but in reality it only has one clear advantage over basic plurality: as long as two parties (candidates) stay dominant, it prevents a spoiler vote. ITTR shares this advantage, while being much simpler and less prone to misinterpretation.
But really, what's the point? The original question seemed to be persuant to what you should advocate as a reform to a manual runoff election method. The obvious answer is approval voting. Easier to explain, no change in voting equipment, cheaper, better.
