Unless you're absolutely dying to have battles with random people online, I'd say this game is not worth it.
I bought this game the day it came out, and I seriously feel like I was hoodwinked by Nintendo. It's lacking features that even the original Stadium had.
I was a big fan of Pokemon Stadium b/c of the mode that let you play the R/B/Y games in triple speed.
Stadium 2 was great b/c it had all those minigames, and again the gameboy player.
Coliseum had the pokemon that you couldn't catch in the GBA games so you could transfer them back to your GBA cart, as well as the single player story and questline.
Now, in Battle Revolution, you get none of that. You can copy your pokemon to your wii and battle with them there, but that's it. Nothing transfers back to or affects your DS game in any way. You can't earn XP and move them back, your battle record on the DS is completely separate, and there are no pokemon to catch on BR to take back to your DS game. In short, PBR has very little to offer other than making yourself a semi-customizable avatar and playing random wi-fi battles.
Just my $.02.