Is the new TNA video game worth buying after buying WWE SvR 08?

I reserved WWE SvR08 for XBOX 360, which comes out in November. But I am not sure if the TNA game is even worth buying if I am already getting WWE SvR 08. I mean, from the gameplay video I saw on Gamespot.com, it seems to be almost the same. Except for the different superstars and arenas, and 6 sided ring, the actual gameplay seems pretty much the same. It has diving moves of the top rope, it has jumping moves off the top rope, it has grapples, strikes, and it even has environmental hotspots. The gameplay seems pretty much the same, so I don't know if the TNA game is worth buying. It looks different on the surface, with the different wrestlers, arenas, and six sided ring, but when it gets down to actual gameplay, it is pretty much the same. So I want some good reasons why the TNA game is worth buying if I am already getting WWE SvR 08?