Fallout 2 is built over the foundation that Fallout 1 started, but richer in terms of content. The SPECIAL system remains as intuitive as ever and most quests have multiple solutions to accommodate for different builds. As an example, I was very surprised that you can plant live bombs inside people's pockets for stealth assassinations.
The story and characters are something truly special, they really don't make them like this anymore. Naturalism isn't the preferred artistic current for modern video game writers.
The only thing I dislike is the abundance of bugs and technical issues. I recommend installing the fan made patch for a better experience.