I'd rather not have a manual safety at all. (A decocker is nice, and I did mention that I like how the P99 has its button flush with the slide.) If I have to have one to get the size I want here, one is better than two and for more reasons that just adding extra width.
I didn't want this to be a forum on the pros and cons of different actions styles for concealed carry, but I suppose I should explain why I prefer DA/SA with no manual safety. Here is my "position paper" on the subject.
1. Safeties
In the heat of the moment, should my life or the lives of my family be threatened, I only want to be concerned with one control mechanism. In any of the potential situations that arise, I only want one thing to be
necessary for fire. Naturally, that reduces to the trigger. Sure, you
can thumb-cock a double-action revolver or some of these hammer-fired DA/SA semis if you want to, but you don't
need to.
Yes, you can leave a safety off but
ideally, I'd rather not have extra fiddly mechanisms that I'll never use. Two buttons are worse than one and one is worse than none.
Sure, I understand that I might sometime possibly need to use one of my range guns or another person's carry gun for defensive purposes and I need to be proficient in a wide variety of actions. That's fine. This is how I want
my carry guns.
2. Action
However much it may or may not be a realistic concern, I'm not personally comfortable carrying a hair trigger in my pocket, on my belt, or under my shoulder. So, the one mechanical remedy that does not violate point 1 is a double action pull on at least the first shot. I also have double-action revolvers in my carry rotation and for home defense, so it maintains some degree of consistency.
Sure, having a different trigger pull after the first shot can take a little getting used to. Training is the obvious answer and I think this concern is largely overblown when it comes to defensive handgun applications. Of course, I did start on this kind of action and it's how I use these particular guns when plinking or at the range.
This works for me. Use what works for you.