Long or Short Performance TOR's

I have long slash cut TORs - to my ears they're great, nice rumble cruising, bit of a snarl revved up. No other performance mods made. I read on one thread either here or BA.com that someone had problems with the short pipes because the end of the exhaust is vertically below your head, rather than a foot or so behind it, so the noise level to the rider was a lot louder, especially when wearing a full helmet. He changed from short to long. No idea whether that would be true for everyone.