Ok, i've done massive amounts of research because I was in your shoes a few weeks ago. If you want a non-bias answer go to
http://www.cnet.com and look at the video reviews of the micro and ipod mini.
The Micro is the way to go in my opinion (what I have). First of all, it's a 5gig (soon a 6 gig version is coming out) compared to ipod mini's 4gig drive. It has a radio tuner in it. You can record from the radio (don't know why you would want to though). it also has a built in microphone so you can record voices and such. The zen's sensitivity is not bad at all. I find it very very easy to use (best way to go is just go to the nearest electronic store and try 'em out for yourself). As with Judas' problem and the pocket, all you have to do is flip a little switch on the top to lock it. You can play football with it and it won't change settings when it's on lock mode. I also like how you can edit and customize all of the screens in the zen micro. The battery life is a long-ass time (no where near 24hrs but you get my drift). I do have another battery even though I never really need to use it because I just hook it up to the USB port at night and it'll recharge.
The zen's software is very nice. It's really really easy to edit all of your song information. It comes in handy when you have to fix 837 songs that are named, "Jazz Miles Davis" when they aren't even miles davis. It's real easy to upload songs from CD to your zen micro as well.
The size of the micro is amazing. It's is smaller than my cell phone and is very light. You can see all of the stats on
http://www.cnet.com again.
BTW, I got my zen micro for $217 with overnight shipping. I think I got it from
http://www.ecost.com . Just check around online before you buy it in the store because chances are, you'll get a WAY better deal on the good ol' interweb.