I'm planning to upgrade my camera body, and I'm curious about whether anyone has used the Eye Control system cameras from Canon--where you look at an autofocus point to select it as the active AF point. Is it worth the extra money? Is it reliable? Is it easy to use? I've heard some mention of "training" it; is this true that you have to train the camera to recognize where you're looking? Current body is a Canon Rebel GII, which I picked up at Wal Mart because I a) didn't know better; b) wanted to get started without spending too much; and c) it was the only one available locally. It's served well, but after researching and taking a few thousand photos, I've realized that more features would be gooder--and some are indispensible, now that I've used cameras with features the Rebel doesn't have. Not that any of that particularly matters; I'm just interested in whether the Eye Control is worth the extra outgo. Thanks!