Unfortunately, the differences are personal preferance at this point, I liked the punch and lower note the PB12 had compared to the 350, yet I also liked the expansive sound the EP350 has and still maintained a nice punch to it. Is the extra bit of lower play and punch of the SVS worth $125? Only you can decide that.
Is the notion of being able to match your speaker finish with the sub worth anything to you, or are you going with black. A significant other in the formula for input into the matter? My wife didn't care if the sub matched our speakers aesthetically.