I am 6'3, 230 lb's and have an arm span of 78 inches. I am trying to choose between a L and an XL.
I would say you would be better off in an XL
it might depend on how you're planning on wearing it... The DAS is oversized and designed as a belay parka to be thrown on over everything you're wearing, hard shell included. If you just want to wear it as a jacket over a base layer and possibly mid layer I think you could sneak into a large. XL though though if you plan on using it as a belay parka and need the extra space. hope that helps, good luck