This is a good discussion. I agree with Don, that the only thing that matters is how the rod casts with a line on it. You can tell almost nothing about the performance of a rod by waving it around without a line attached to it. A good analogy: judging a fly rod without a line is like judging a guitar without the strings - you're only looking at half of the tool.
The only thing I would add is to be careful when somebody generalizes about "all graphite rods" or "all Sage/Orvis/Loomis etc. rods" and says "all graphite rods cast better when you overline them (or underline) them by one line size." Only the caster can make that decision and it will not be the same with all rods. Moral here? Cast the rod before deciding if you like it!
When I was working in the fly shop, many years ago Orvis brought out a nine-foot - 4-weight, three-piece rod called the Zephyr. When you picked it up off the rack and waved it around in the shop, it felt long, slow, and noodly. When you put a line on it it became precise, elegant and beautiful. People hated this rod because of the way it felt in the shop, and nobody ever bought one.
Jim