Some WorldGenerators have stability-issues and sometimes create corrupted chunks. This applies to almost all competing world generators of RWG.
RWG itself is created to prevent such things. To improve stability and prevent corrupted chunks RWG does not hack into Minecrafts code, like some competitors do.
This often can lead to crashes and corrupted chunks, while they sometimes get minimalistic performance-improvements.
We ourselfs have decided to use a bit slower method, but more stable-method to hook into Minecraft's code.
This in the end makes RWG easily upgradeable from one version to another without corrupting chunks or having bad edges/corners at new chunks.
To even further prevent your server from having corrupted chunks we detect issues already on startup and inform you about them, before they occur.
This overall makes RWG easily upgradeable without having the need to fix chunks or smooth them yourself.