For me personally, it's just too much. Small greyouts on other rides don't bother me nearly as much as I305 - the after effects of that one seems to just stick around all day. Other rides are more "whoa, intense, all right, keep going." I305 just feels like getting knocked on my ass and kept down.
One of these days I'm going to drink a gallon or two of water and then ride it, see if that makes a difference. Or maybe I'll just pee my pants!