I have pretty much given up on MJ8. Performance on my system is extremely poor, and I have a relatively high-end system (1GHz, 512MB RAM, 40x CDROM/DVD, SBLive 5.1 Platinum, drivers updated routinely...)
Granted, I am running WinME, but I have only had issues with very few programs, MJ8 being one.
The MP3 encoder in MJ8 will rip about half a disc before it hangs the system. None of the "fixes" improve performance, and Tech Support told me to turn off my CD Digital in. Why? Works great with everything else. Killing Digital in will reduce performance further, and reduce quality of tunes.
Creative PlayCenter will rip at same bitrate with equivalent quality sound in less than half the time.
It's a shame. I really liked the earlier versions of MJ, and the features of MJ8 are awesome. I just cannot justify spending days of effort to adjust and tweak my system for a piece of entertainment software, when I already have others that work fine as-is.
If you are going to go with MJ, I recommend the earlier versions, depending upon your OS.