I don't know. I am several years older than you and don't get anywhere near 70 days a season (even when adding in splitboard days) and would get the Chairman X if I was in the market for a new board (which I would be if $$ were no issue).i am not a snowboard expert too!
i am 37 years old , i ride for 17 years, i ride the same days like you per season , and i have only one board to do it all. powder , piste , ice like you .... that's why i need your review too ...
i am not an expert . i think the chairman is for the expert with 70-100 days per season with the legs of steel
the west is more versatile for most of the conditions i ride .... it's the wise choose i think
I would definitely say I don't have legs of steel. But, it sounds like you are leaning towards the West. It could be a great choice if you want that softer flex. I rode it only once (it was actually the split version) and it did have that softer feel people describe as "playful". I was able to flex it at the waist and kind of choose the angle I wanted to place the tail at when doing -especially- heelside turns. It was kind of a unique feeling.
I have some video of riding the Chairman X on Youtube, which may, or may not, be useful.