i just got a 40 cu ft stage bottle. I am slowly transitioning toward "tech" training. Would a mares MR12 work as a enrty level stage bottle reg. My primary is a Apeks DS4/TX50, I'd like another one of those, but don't have the cash for it, as I want a bp/w next. I can get the mr12 used, fairly cheap. I would plan to eventually add a O2 ready TX40 for the stage, once I have more of my kit assembled. I will be diving colder water 40 degrees and above in the great lakes, down to 130. For now, until I finish my training, the stage bottle, is just for weight/trim practice and as redundant air supply on NDL dives.