Overall this game is excellent to play in S3D, you can enjoy the entire game in S3D without much problems.
Caution : the in-game screenshot function interferes with the Tridef screenshot function. Make sure you remap the ingame screenshot button or your screenshot will be 2D.
The ingame Stereoscopic tickbox is not available with the Tridef driver. As a result, the HUD and mouse cursor remain at screen depth, the game character creator and story cutscenes are made of series of 2D backdrops rendered at screen depth and with 3D characters rendered behind the backdrop depth with a convergence setting which makes the characters appear almost flat.
You can tweak the convergence in the character creator and cutscenes to make the characters appear at the proper place and with a good amount of volume, however this setting has extreme convergence and separation settings, It's reasonable to do it for the character creation but not for the quick cutscenes since you will have to change the convergence settings again for normal gameplay.
There's a minor bug when rendering water reflections at max setting : your character's reflection disconnects when adjusting the 3D effect, the rest of the landscape reflections are fine. This won't be much of a problem since there are very few places where you see your own character's reflection, and most people will reduce reflections to sky and terrain only since max reflections eat up a lot of framerate.
The Framerate performance is heavily tied to your CPU performance. GuildWars 2 is CPU-limited. It's a known problem even when playing in 2D. Areas with lots of players will hurt the framerate even in 2D mode.
Part II: Required Game Setting Reductions & Adjustments
Total penalties: 0
Part III: Top Level Anomalies
Total penalties: 0
Part IV: Secondary Anomalies
Total penalties: 1