Giving this a go on my Nforce2 system for obvious reasons. I have only had 2 big issues so far, neither game breaking and only one fault of my own.
ME setup installs a "Crystal Soundfusion" driver for my Turtle Beach Santa Cruz, which causes a blue screen with a vnetbios.vxd (I don't recall exactly) before the setup is complete. Took me forever to figure it out. Windows 98 does not do this as it doesn't have a clue what the sound card is at setup. I didn't catch this when I first loaded ME because I had an Audigy 2ZS installed. After I broke ME with the next issue I will describe, I went to reinstall with the Santa Cruz (love the slim drivers) and got this blue screen over and over. I first assumed it was related to the Nvidia ethernet, because of the name of the file in error. That didn't make sense though as I had it enabled when I installed ME the first time. Disabling the NIC also didn't fix it. I removed the Santa Cruz until Windows was fully setup, then I installed the card and rebooted. I canceled any prompts for driver install, then installed the proper driver from Turtle Beach. Good to go now.
The second problem is most likely my fault. I believe I may have inadvertently installed an Active Directory update intended for Windows 98, which broke the file sharing tab on folders. This lead me to reinstall ME, which caused me to spend hours in the Crystal audio nightmare.
On a positive spin, it runs MUCH better overall on my Nforce2 system than 98. ME doesn't complain about being setup with 1gb of RAM installed (I haven't tried 2gb during setup). I also don't get the issue with too fast of shutdown causing scandisk to trigger which is a major pet peeve of mine. I'd highly recommend it for any late 9x system that's overbuilt and not going to run native DOS due to sound issues or whatever. It doesn't hurt that I love the icon artwork of 2000/ME; they are my favorite icon sets of all Windows. I ran 2000 back in the day for as long as I could and ME is giving me a similar vibe now.