Replying to Ipod vs. Creative Zen

I was wondering if any of you have a take on either of the 30gb players of Creative or Apple. I was contemplating either buying the 20gb Ipod, the 30gb Zen Vision or even the 8gb Zen micro. The main reason why I would go with a lower memory is that this device has a replaceable battery. I bought a Ipod shuffle not even one year back to ski (was afraid to break a bigger player) and it completely died out on me (sadly cannot find the bill). The new battery will cost me as much as a new player so I might aswell get something with more memory. Any takes? I'm leaning towards the 8gb just for the replaceable battery and no hassle sending my player back but a bigger memory would be appricated (have to send those ones back if they die out) thanks.