Basically, you need to look at PBR for what it is. It is a Pokémon battle simulator and nothing more. No storyline, no catching and training, no minigames. It is straight-battling, so if you are into that, you'll enjoy it. The highlights of buying the game are the ability to battle, in 3D, against other people (randomly or not), and also, the ability to battle in-game for prizes that can be sent to your DS game.
If you don't have D/P, you won't enjoy this game as much.
If you don't love or excel at battling, you won't enjoy this game as much.
If you are disappointed by the lack of Wii-enhanced gimicks, like swinging a Wii-mote around...Super Smash Bros. Brawl doesn't have that either. That is all I have to say. XD
Buy it if you love battling and really would love the ability to battle random people, instead of asking for friend codes and setting up a battle beforehand. Though if you can wait for a price-cut, or find a used version, that is always good too. x_x