+1 for the review, the freebird is now on my short list where as it used to not even be on the radar.
I've been a consistent buyer of Ion's (5 pairs) over the years as well as cartels and CO2's and I've found that burton stands behind their products. Aside from the 2008 - 2009 Ions (green/white) which were a disgrace and felt like sorrells after 20 days, the ions have been awesome. If you're patient you can always scoop a pair up in the spring for +/-50% off. I paid $150 for the green/white ones so I wasn't that sore about it, if I had paid full price they would have gotten an earful from me and I'd like to think they would have made up for it one way or the other.
You do have to give them props on the AK line, fit, form, function and lifetime warranty, tech outerwear with steez. I have a pair of 2l staggers that I love, they're a little heavy and baggy for splitting but so well thought out and designed that I just can't bring myself to drop $400 for 3l's, arcteryx or any other more split 'specific'/backcountry pant. I also have a couple buddies that had issues with some 2l and 3l pants after heavy, heavy use and burton has replaced them no questions asked. When I was in LCC I noticed AK pants seemed to be the choice of 'bird and alta patrollers.