I"m looking at purchasing one of these kites. Which one will be better worth it in the long run as far as durability goes?

I've flown the Beamer.......very durable kite. I learned on it and have flown it hard and it still flys great. I don't have an Imp but have been very impressed with the durability of my Ozone kites as well. I don't think you can go wrong with either kite. I have a personal preference for Ozone kites over HQ so I might opt for the Imp depending on how much more expensive it is than the Beamer. I assume you are talking about a 4-line Imp. I'm not sure what the Imps are made of but I LOVE the 40D ripstop that Ozone uses on their snowkites.