I have the Creative Zen Micro and I love it. To be honest my needs are pretty simple and I don't have an extensive music collection so I don't worry too much about tagging etc. The Micro has a radio which I find great, it's nice to have the option. it does crash occassionaly, esp after charging it up over night - but turning it off and on again ususally sorts that out. I'm surprised about the warrenty - mine died after having it for about 8 months - I didn't check the warranty but I called up customer service and the changed it for me straight away.
I think the customer service issue is a big one. Everyone that I know who has an ipod has had some issue with it (crashing, batteries dying etc) and they've found it hard to get to talk to someone about fixing it. I think creative have a call centre in Blanch so its really easy to get in touch and get the device sent back etc.
Let us know what you decide to go with,
Gnash