Depending on your ISP this is basically a non issue. I know with AT&T here they say it's a "direct line" and doesn't have any fluctuation based on your neighbors usage. You're right though, particularly if it's based on an older cable/coax signal.Theoretically, going to a higher tier usually means they give you a higher bandwidth allocation which is great during peak times of usage in your neighbourhood. You'll feel less of the throttle when your neighbours are downloading big files.