Tav compared to The Darge Urge to me felt like playing two different games, The Darge Urge to me feels more fleshed out and reactive to certain points of game, like its the DLC we never had.
Comparing The Darge Urge good and bad sides of a run however only feels different in Act 2 and Act 3 depending on the choices you choose to pick which are durge related, so if you can get past Act 1 you should definitely try both good and bad side!
Not going to spoil anything but if you want to experience all sides of The Dark Urge, two runs are pretty much essential!