great, another "holier than thou" convert
Anyway, back to the "will you notice a difference" question. Lighter weight wheels is a plus, but is not the end all be all of choosing the right wheels. I'm also currently on WH-R500 that came with my bike, and I can't wait to ditch them. They do not suit heavier riders well, they go out of true, and ride quality leaves much to be desired.
I wouldn't look at ONLY saving weight. I would look for a strong, durable rim (of your choice, the pro/cons of al/carbon have been beaten to death), with a good hub, and a spoke count to support your weight. You will probably end up saving weight (though probably not 400g) but will mainly end up with a good wheel suited to how you use your bike, not a cheap of the shelf "solution" that is really just a big compromise
Last edited by BTM87; 09-27-12 at 12:23 PM.