I've had either a ZIP 100 mb. or a ZIP 250 mb. in constant use for at least 10 years on two systems and never a problem. I do agree though that they are yesterday's technology and there are much better ways to go now for data backup. Still, I use older USB ZIP 250's to store all my doc and banking files weekly. I burn my 500 MB Outlook .PST file to CD-RW weekly as well, as that one is my life in a single file.
A few years ago when I built my current system (long overdue for replacement) I invested in several of the Exa-Micro removable HD trays for the full tower I was using. A 5.25" HD lays in each one, and they each have external fans and install directly in the full height bays. I bought Power Quest Drive Image and with a supply of extra hard drives, just clone the master drive and pull it out on the tray and store it. The advantage of this has been made evident when I had my primary HD fail. I just slid out the bad drive and slid in the week old cloned HD and rebooted, and was back up in minutes, with all data intact except for those mails in my Outlook .pst file that I had received since the last backup. A few emails was not a big price to pay. I tore apart the old Maxtor hard drive and scavenged it for drive spacers and magnets and then tossed it. Compared to the old days when I would have spent 2 or 3 days reinstalling the OS and all apps and trying to recover data files from the damaged drive, it was effortless. Minutes instead of days.
You can also fill up one HD and then pull it out and slide in a new one. The BIOS auto-detects the new drive as long as it's jumpered correctly and you are set to go. I have 5 or 6 now old 20-30 and 40 GB hard drives and can swap them out when needed, each in their own tray. To free up the maximum # of E-IDE devices on the board, I bought a SCSI CD-RW with an excellent card (Adaptec 29160) and kept a DVD-ROM as the primary slave and HD's on everything else. I have to get back up to speed on this stuff; 5 years ago this setup kicked butt, but now the new stuff is light years further along, and HD's have gotten massive. The biggest I have is 80 GB, and 5 years ago no one could touch that. Now 300 gig drives cost less.
Time to get a new motherboard and rebuild the next gen system, but the days seem to be gone when it was majorly cost effective to build your own. The Dells and others are so cheap now that it is almost easier to buy direct and just add peripherals (such as external USB hard drives) as needed, and I may just do that. (My 17 year old daughter is now the youngest employee of the new Best Buy store in Salinas, and I'm eligible for her employee discount! I have visions of a new notebook to replace my 5 year old Winbook XL3 and a new Dell desktop. Just need some $...)
As a veteran of slow backups to optical disks and ancient Colorado tape drives, all I can say is whatever you use, backup, backup, backup!
FYI, my son just bought a 1 GB. Memorex thumbnail "drive" USB backup for $50! Plug it in your USB 2.0 port, download and carry it in your pocket. Amazing...
Norm