My daughter's gaming rig is 3D (3D Vision) 3xHD (5900x1080) w/bezel correction. She swears by it (3D Vision) and that 3D is simply a great experience -- once you have the everything properly setup and the monitors calibrated.
Just know upfront everything costs double or more, and ditto with the requirements.The newer monitor's offer LighBoost which is a very good idea and is strongly advised. I've been trying to upgrade the GPU's to 4GB versions of GTX 680's in 3-WAY -- I'm still waiting -- plus I need versions that either EK or Koolance support.
Cons = #1 Price
If I/She had the choice between 3xHD (Surround (2D)) VS 1xHD (3D Vision) then ... go 2D route.