anyone with 15 seconds of time can figure out how to use it.
I think you just perfectly summed up the objections of every diver who has carefully considered combo rigs vs standard octopus rigs and has decided to pass on combos.
I don't think any reasonable person can argue that a combo rig is as simple and intuitive to use as a standard octopus rig is. It is not. Period. You breathe through a standard regulator 99.99 percent of the time you are under water and most people adjust their buoyancy by purging their BC with the hose over their head. In an emergency, you will have to do things differently.
So, then the question becomes: am I confident that, in an actual life threatening emergency, I will be able to think clearly enough to remember to do things differently than I do them 99.99 percent of the time I am diving. If your answer to that question is "yes", and you are willing to make a high stakes bet on it, and the luxury of having one less hose is worth whatever you assess the risk to be (because it is NOT zero), then a combo inflator is a logical choice. For many of us, it simply is not.
If you have not been involved in a real emergency, you do not know how you will handle the stress and panic involved. People do not think and react normally with a liter of adrenaline coursing through their veins and while dealing with a diver who has been without air.
And for those of you who are getting defensive about this discussion, remember that we are not trying to win an argument. We are trying to share our experience and explain the reasons we have reached our conclusions. We think it's safer.
