I'm suprised no one on this post has mentioned Rick Bin's The "Big Eye's" Revolution article at :
http://www.24hourcampfire.com/index.htmlThey rate the value of these very high. Quality not quite what the Swaro's provide, but at 1/3rd the cost. I'm sure Doug is happy to fill the Swaro orders if you prefer.
I would love to hear more about the difference between these and the 13x version I have read so much about.