AF accuracy with fast lenses and outer AF points

I currently have a 500D and I sometimes get a bit annoyed when the outer af points pick up the hair light or something else when shooting portraits in portrait perspective when using the outer af points. I do understand why it happens since they aren't cross type and why it sometimes picks up the hair light instead of the eye.

Then I looked at the 7D etc, why is it it's always the center point only which is for f/2.8 or faster lenses. Is it better to use the center point with a f/1.4 lens and slightly recompose or just use an outer point considering it's not as sensitive?

Does the center point require more space or why can't more points be sensitive to faster lenses? What about you people shooting with fast lenses such as f/1.2, do you find the outer points accurate enough on camera X? or do you prefer to use the center point? I'm talking mainly portrait work.

I guess I would just like more cross type points for my portrait work I'm a bit scared by all the topics about people having issues with the 7D af, 60D might be an option as well for me. I'd love 8fps when shooting agility but I rarely need high burst speed. Oops, this should have been in the camera section, sorry.

do you mean the outer AF point picks up the hair light when you've got it positioned on the eye? Or when you have another AF point placed over the eye, and one of the outer AF points that you aren't intending to use picks up the hair light?

I always only use one af point, it's just sometimes when the af point isn't exactly over the eye but a bit closer to the edge it backfocuses from time to time. In very low light I find it a bit hard for the outer af points to grab focus when it's completely fine if I use the center point. I was just thinking it would've been better with all cross type points.
Meh I couldn't find any good sample pics when quickly looking, I usually delete them immediately.

Thats because the hairlight has much higher contrast than the eye, so the AF sensor will pick up the hairlight more easily than the eye, any camera will probably do exactly the same, you won't see better results with the 60D. You just have to recompose slightly to make up for it, or manual focus.

Thanks that's a good tip! I'd just move the af point a bit closer to the nose and then back for the specific composition. There's still the low light, low contrast issue though

Here's a quick example with the canon 17-55, where the outer points struggled but the center point was fine. Keeper rate was around 50% with the outer points, this is oof, wouldn't a 60 or 7d focus better in this light?

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I can't say for sure, but in situations like this I'd guess that the 60D and 7D would focus better as they have more cross type AF points. However, its best to just use a flash or ST-E2 with focus assist in really dark scenes