I'll fill you in on my overall experience with Debian/Linux on the zt1170.
Debian has worked great. I still had one of the stable release (2.2/"potato") cds I bought from a vendor off the Debian website (I wanna say around $20 - though if you have cd-burning capability you could just download and burn the cd yourself). and immediately upgraded over the net to the testing release (3.0/"woody"). Upgrading from one release to another in Debian is an easy configuration change. I did not stick with Potato b/c I find that one of the problems with Debian is its conservatism - only truly stable programs make it into stable and once stable's released, it's only updated for major issues/security problems.
My other thoughts on Debian: package control is excellent, but package configuration is not always easy. You have to be willing to edit config files by hand and spend some time at the ldp pages. Debian does seem to keep one of the strongest committments to open source though and there is good support available on the various debian mailing lists.
Successes I've had do include USB setup (which I noticed as a question on your page). I have a Yamaha YST-MS35D USB speaker (3-piece - subwoofer and two satellites) and a Y-E Data USB floppy drive, both of which work great. I should note that these may take a little bit of kernel tweaking - in addition to the basic usb drivers, I needed sound support and usbaudio for my speakers and for the floppy I needed a combination of usb mass-storage and the scsi disk driver. Linux apparently treats any type of usb disk drive as a usb-scsi adapter connected to a scsi disk/cdrom/whatever. My USB printer however (a Lexmark Z33) is basically a paperweight under linux. That's my fault though for buying before I consulted linuxprinting.org.
I've also been able to setup windows filesharing with samba and apple file sharing through netatalk (my campus has historically used an appletalk network, though support for non-apple computers has expanded recently). My only unresolved problem with netatalk has been setting up guest access, though that's certainly an issue with netatalk not the laptop.
My filesystems are a little interesting. As I said earlier, I keep most of my important data on a vfat partition for easy access and long filename support under both oses. I'm also experimenting with using a umsdos partition for home so I can have access to my home directory in windows. The rest of my linux distro is on a set of ext2 partitions that I've now upgraded to ext3 (huge recommendation there - the journaling features have saved me several times from data loss when my system froze while I was experimenting with different DVD software).
My only outstanding issues with the laptop are DVD movie playing and ACPI power management. I am able to mount cds/dvds in my drive fine, but I have not been able to set up the software to play movies - I'd appreciate any info available on that. I also plan to experiment with the acpi info you just put up. I'll let you know how that goes.