Guys, Thanks a lot for the answers!
Seems like, even after many years away from the community and the machine, I'm still kind of "up-to-date"!
Well, I'm not a heavy MOS user. Never been, except for like 6 - 12 months. I would surf the web or play videos only ocasionally, just for fun. My Pegasos is one of my vintage machines, and I use it accordingly.
I'm still using MOS 1.4!!! I also have MOS 3.x (can't remember the exact version) installed, and I like it very much, but never got around to register because I wasn't sure if I would keep the machine.
Also, my MOS 1.4 installation is really nice, I like it a lot! Everything is already very fine tuned. The only problem I have is that at the first boot everything is fine, and subsequent boots will come up as a garbled screen. I have to boot it multiple times to have a proper screen, and sometimes I just give up after the 10th or so try. By garbled I mean you can't figure out what's going on. You can see the pointer moving, but can't even recognize it's the pointer, unless by seeing it reproducing your mouse movements.
I never found a solution, neither know if this is a known issue. But would love to find a fix for it, even if I register and use a more current version.
I think I'll keep the Pegasos and register MOS 3.x. The team really deserves it, and it's a piece of history I want to keep. My only concern is if the Pegasos die on me.
I know Mac Minis are dirt cheap these days. Even here in Brazil you can find some at reasonable prices. I may grab one to check how the system performs. But I feel more comfortable with the Pegasos. Even if it's just an ITX board, it feels more like a proper MOS machine.
Thanks in advance for all the help!