Why settle for anything less?
Because it seems like a lot of effort for something amazingly minor? (Really, except for peering around corners, which is a function in almost every stealth/cover-shooter game regardless of whether you can see your legs, what does that stuff in Arma really add? It didn't do anything for me. Sorry. Guess it's just one of those "have to agree to disagree" things....)
...and that Far Cry video was terrible. The first half being mostly at night didn't help you see anything, it didn't look like there's any "see your legs" type stuff, and the running animation (where the guy was sprinting with his map & PDA out) looked awful.
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Disclaimer, just to clarify my general viewpoint - most of the threads in the last few years where the word "immersion" has been thrown around, have led to me having an instinctive reaction toward the word like most people have to that essentially meaningless business-speak stuff like "leveraging the commodification of our shareholder value" (/vomit). And I've generally come down on the other side of most of the things people were claiming was "better"
(for example - people pre-FO:NV were clamoring for the need for "iron sights". I hate them. I was glad you could turn that feature off, because the FO3 method - gun to the side and crosshair in the middle, was far superior... all those sights did was clutter your view and make it hard to aim at stuff. Ditto in Borderlands... except for scoped weapons, I never aimed any of those guns because the "iron sights" made it much harder to hit stuff.)