As others have said, it's a great game with lots of content. The GOG version should work on most systems, but the game will need the unofficial patch - otherwise, there are plenty of bugs left, plus some missing hints, dialog items etc. that will make for a confusing experience.
This patch now also includes the high resolution patch, along with high resolution town maps and audio. The high res patch is also recommended since it improves compatibility with modern systems.
Don't know why they used the term "dozens", maybe they meant mainline quests. There are hundreds of quests from what I remember (some are pretty simple though).