Yeah, there's a lot of pitfalls, but this specifies no downsides what so ever. So I assume it works like Wally West-- you can have a conversation at normal speed or zone out so you can run across oceans without getting bored. You also stay mentally well adjusted while being able to effectively live infinite life times. And your speed reflexively kicks in when something blows up or a bullet touches your skin. (Or for some reason when your boring father on law starts telling a story, which is the worst downside I've seen for Wally. But hey, even that is cured here.)