I really can't comment on the active samsung you are gonna get. But I have owned both active and passive 3D sets now. First a 50st30 panasonic plasma and just recently an l55et5 panasonic passive LED. I do plan to game on it (PS3, WiiU) but both TV's were PRIMARLY for 3D. So speaking to you as a 3D fan, passive 3D blows active 3D out of the water. Yes it has lower res, which is a negative. But every single other catagory it destroys active.
It seems more natural maybe becuase there is no flickering causing no eye strain. The 3D seems to have more natural "depth". The image is just as bright with the glasses on as it is with glasses off. This is easily noticable if you take really impressive bright scenes like the bright gold of Rapunzel's hair when it lights up in tangled. So if you are a person who likes to watch movies and games in "vivid" mode, you will be pretty dissapointed in active for that reason.
So yes, I think that you will regret it. Just accept the TV you have now, and a few years down the road when you can get a mid size 4k tv for a good price, upgrade then. Then you will have twice the res and it will be the best of both worlds. But at this point given passive vs. active flaws, passive beats out active hands down in my book.
Denon x4000 (o)c (0)
SVS PC12-NSD + Klipsch RW12d