I just had a game where the guy who was designated support, showing Zed, asked to swap to play mid. He said "you can play Brand support, is good." Mid didn't reply, and myself and our last pick (who was top, showing Garen), said "please don't do that." So, support guy goes "Fuck you." and then bans Garen. Luckily, someone dropped out of the queue at that point.
Dynamic Queue has its time and place, and is fun sometimes when you're in the mood to draft and not play ranked. But really, I just like being able to log in and pick the champion and position I want to play and not have to worry about crap like this or playing blind pick, which is more of a gamble or "who can be the biggest jerk and instalock quickest" competition.
Removing old Team Builder was stupid. Replace blind pick with old team builder. It's practically the same thing, you just KNOW what position you're getting and you KNOW you will get to play the champ you want to play.