yoda

I am in need of some help. I am in the market for some new boots and looking at the Burton Idioms and the Celcius Cirrus. I ride basically all mountain, through the trees, butters, started to hit up some boxes, but also like to hit pow runs as well. I was wondering which boot would best fit my riding style ? are both boots true to size or will i have to size up or size down?
Thanks for any help