OK I found it. This link to the Army Times was on HKPro, I just had to search the memory banks to remeber where I found it. They are comparing the HK416 to the AR-15. This is by far the best illustration of the two rifles I have seen, it's pretty cool to watch actually. OK maybe it's becasue I'm simple to amuse .
BTW the HK416 is awesome but for the most part cannot be had by mere mortals. Dealers that have them would rather cut them up and sell the parts kits as they can make a much larger profit that way. FWIW[/url]
I have a Bushmaster M4A3 and it works great. But, if it's on a XMAS list You may want to consider the SIG 556 for an extra $200. I picked one up from Becky at Sporting Arms a few weeks ago. It's piston operated and runs cleaner, and more reliably with less maintenance. Bushmaster makes a piston operated upper as well, but it is more expensive.