Put me in the no manual safety camp. If a gun has a trigger too light to carry without a safety, I think it's too light for CCW - for me.
Manual safeties that go down for fire can easily be swiped off during the presentation, true. They can also be swiped off during the draw or even inadvertently swiped off while acquiring your grip (google Tex Grebner), which basically forfeits almost any ability to prevent an ND. This is the reason I wouldn't carry a firearm with a light trigger, just because it has a safety. If you're carrying in a holster, this type of manual safety is little more than a reholstering aid. I don't plan to reholster in a hurry. If I need to discard my CCW in a hurry, it'll be because it's empty.
Also, depending how you grip the gun, it's possible to accidentally flip a frame mounted safety to safe. When I'm done messing with the safety, I'd rather it be nowhere near where I can accidentally hit it while shooting.
So if it does have a safety, I prefer the spring-loaded slide-mounted safety of the Beretta/Stoeger Cougar. It's almost impossible to accidentally trip while acquiring your grip. It's more a matter of gripping first, then once you have a good grip (and only if), the safety can be flipped off quite fast, during presentation. Not easy to trip during the draw.The spring-loaded part also makes it very difficult to accidentally put on safe and impossible to put to a position halfway between safe and fire. It's quite a nice safety. I feel like the safeties on all my other handguns are vastly inferior. Ironically, I gave away the Cougar for other reasons. As someone who doesn't like manual safeties on a handgun, I sorta miss that aspect of the Cougar. Everything about it was perfect - placement, lever shape, feel, etc.