I have used aspen and cypress up until recently when i ordered unprinted news paper(2 weeks ago), and i will never go back. they all have there plus sides and downsides. i would say just use the aspen up since you have it. It most likely will not cause any problems unless your bp eats a huge mouthful of it. I love the look of aspen and cypress but to me the look vs the price/easiness to clean is not worth it. i still use aspens for my corn(loves to burrow) and my carpet get cypress because she's in a big display cage.
use it up and then after its gone decide do you want to order more or try something different, its all up to you.
Tom