I prefer flash over second wind for warriors by a mile currently. I tend to find it allows me to move mobs a lot less which ultimately means I can make more use out ground effects like flaming arrow, doton or shadow flare...

but this is partly down to the annoyance I get as a ninja or scholar when I drop a shadow flare or doton and the tank pulls all the mobs out of it so he can line up an overpower to hit a couple more adds
I mean sure the shadowflare doesn't do a massive amount of damage. but the slow effect is a fairly effective mitigation tool.