The model we received (quality grade: C) features a 400 Mhz G3 CPU, 8 MB ATI Rage 128 graphics card, 64 MB RAM (we quickly upgraded it to 320 MB of RAM with a new 256 MB RAM Geeks also sent us), a 10 GB Quantum Fireball drive, a DVD-ROM, ethernet, modem, 2 usb 1.1, 2x firewire (industry first at the time), audio I/O, onboard microphone/speakers, 15" XGA CRT, airport-ready. The iMac came only with a power cable and no CDs or manuals, and no keyboard or mouse. Thankfully I had two Apple-branded input devices in my storage room which I successfully used with this iMac.
Once again (since I used to use a G4 Cube) I was amazed at how fast Mac OS 9.2 boots and operates. OS9 reminded me of another era, a more innocent era in operating systems. Today users require so much from their desktop software that developing and delivering an OS has lost lots of its joy. But even today OS9 could serve a less-needy user. It comes with IE, Netscape, Outlook Express and there are still thousands of applications to freely download or purchase. OS9 might not be supported anymore by Apple, but it can be used to fill up most modern needs.
The dream and atmosphere died quickly though after I discovered two hardware problems with this iMac (that also appear on OSX). First off, the ethernet jack was broken. It seems that whoever owned that machine before had no clue how to remove an ethernet cable properly... I had to physically push the ethernet cable in order to achieve connection. Secondly, the graphics card is half-fried: a vertical line follows the mouse cursor wherever it goes and when you use any app that uses overlays (e.g. QuickTime or DVD player) the picture looks like it runs in 4k colors (while the OS runs on millions). Please note that this does not mean that all the units sold are problematic (some are Grade-A or Grade-B, better than this Grade-C). But for old second-hand Grade-C products, you gotta be a bit lucky too.
After a bit of effort fighting with the ethernet plug I successfully downloaded the OS 9.2.2 update and upgraded the system. After playing a bit with it I knew it was time to also install Mac OS X. Thankfully this specific model supports Tiger as it has USB, Firewire, a DVD drive and enough RAM (Panther required Firewire and Jaguar required USB in order to install, Tiger additionally requires a DVD drive). After only about 20 minutes I had an OSX system, fully operational. The Tiger installer kept the OS9 partition and so I can always run Classic applications through OSX, or I can fully reboot to a "clean" OS9 system. Having both operating systems installed, it only occuppied about 4 GBs of data, leaving 6 more GBs available for the user. The Tiger OS updates from 10.4.0 to 10.4.7 were about 400 MBs, but quickly I had a fully updated iMac next to me.
I was impressed by the speed of Tiger on this 400 Mhz G3. I remember a time in 2001 when our ex-housemate bought a 500 Mhz iMac with Mac OS X 10.1.5. It crawled! But Apple has made an exceptional job optimizing Mac OS X since then. Especially with Panther and now with Tiger, a supported 400 Mhz G3 is more than enough for some basic internet usage (browsing, email, IM etc). When my husband came back from work and saw me using this iMac he remarked "hmm, it's not as slow as I remember it". And indeed, it is not. The DVD playback does not drop frames (I was positively surprised), Safari renders pages at an acceptable speed, even this old drive boots OSX pretty fast too. Only h.264 playback proved a bit slow (even on "small" size trailers). The only feature I had to sacrifice in order to minimize memory consumption was Dashboard. After disabling Dashboard and restarting the Dock I had over 150 MBs of RAM to spend. That's plenty of RAM to browse and do IM and email.
The way I see the value of these older G3 iMacs is this: great gifts for small kids (up to young teenagers) or older non-technical people. While they won't satisfy young gamers or business environments anymore, these iMacs still have a place in the kids' bedroom or the office of your grandparents. So if you have newphew, young kids or older parents who don't need "more" or just need an introductory computer, these iMacs are a great deal. They sell between $50 and $100 and they provide the full monty. And if you are a geek, you probably are going to get one for yourself too.