If you don't use Gouge very often (which you may not, especially if you solo through PVE content with swords), then the utility of this talent may not be apparent. The main use for it revolves around waiting for cooldowns such as Kidney Shot and energy pooling. Some argue you can restealth by getting out of combat before Gouge wears off, but on practice combat always lasts longer than Improved Gouge and it is only possible to restealth if the enemy doesn't attack you for about a second. You can run out of range with this talent and restealth, though.
This makes Improved Gouge an invaluable part of PVP stunlock builds, as well.