Anyone prefer not to have AF Beam Assist on?

I haven't done enough tests, but sometimes I feel as though I get less accurate focus with Beam Assist.

Anyone experience this before, or if you prefer not to use it, why?

Thanks!

All it does is give the camera something to focus on. It uses the same AF system.

If I've got good light I can switch to AI Servo AF mode which I normally prefer for "run & gun" shooting. No AF assist light with that mode.

When it's dark, the AF assist light can mean the difference between being able to shoot, or not.

My results are much better with the AF Beam from my 580EX.

Some lenses have AF issues when using flash. Don't know why.

Huh, while I dont believe I have ever had issue leaving it, I greatly appreciate the AF precision and improved performance in lower light situations when its on, so Ive never turned it off.

I don't use the popup flash AF assist (it annoys me), but I find the red AF assist on my 430EX/EX II very beneficial.

Like Curtis, I often prefer to use AI Servo mode...when there is good enough light. I often end up using single shot because I want (need) the AF illumination from my shoe mounted flash.