Hardware ... The Good:
1. Great capacity for the price, the same size iPod is more expensive.
2. firewire and USB 1.1 connectors on the same machine, or you can pick the newer USB 2.0 if your machine supports that.
3. Great display and logically organized menus that are easy to navigate.
4. Can be used as a regular hard disk to moved files around (only some software allows for that type of access.)
Hardware ... The Bad:
1. I personally do not like the buttons. I find them small and not easily distinguishable in the dark. They are not a problem if you are looking at them while pushing them.
2. No STOP function. You can only pause a playing song or turn off the player, there is no actual STOP.
3. "fragile" they don't handle being dropped very well, but that is more of a limitation with HD based player than anything dealing with the Zen in perticular.
Software ... The Good:
1. There are 3rd party companies that are developing software that works with the Zen, like Red Chair software and our friends here at JRiver - so you do not have to use Creative's PlayCenter if you do not want to.
Software ... The Bad:
1. In my opinion, this is where the Zen really falls short. The third party software is simply not up to the task. I love MC9 as a player and media library, but support for the Zen is unstable and lacks complete integration with the device (see my other post about the crashing.)
2. Notmad Explorer (by Red Chair) is very robust in terms of stability, but all it is is an extension to Windows Explorer, it has no music library so you are navigating hard disks to move your musicl; when dealing with libraries that number is the 10 thousands, this gets old very quickly.
3. For Windows XP, Microsft has released their FREE add-on, which lets you see the Zen as a hard disk and transfer files to it. Very very stable, but has the same issues as the Notmad Explorer I mentioned above - you just move around your computer, which becomes unwieldy. You can also transfer files to the Zen using Microsft Media Player 9 (Still my favorite player in terms of control) but that has serious glitches on the Zen, playlists do not transfer as playlists and there is no duplicate-file checking, and some tags do not transfer properly.
4. Creative's own software "works" the best still in terms of control over the Zen, but it is terrible software over all. It looks like it was designed by a child to win an goofy art project, and it has serious limititations for controlling your music files on your actual computer. FOr example, it will not allow you to pick a network mapped drive as the source for your library, and scanning is painfully slow.
I love my Zen, but I am still waiting for that great piece of software that will make it as easy to use when it is plugged into my computer as it is when it is not.
I hope that gives you a start