I enjoyed the game as a fan, but I'm not blind to its flaws. Enemy variety really needed to be stepped up, melee was overpowered, the AI both friendly and enemy was moronic at times, the visuals were.....ok and the overlying story about 'Dark Energon' just didn't cut it for me. Despite that, I had fun playing the campaign and the multiplayer. It certainly wasn't the solid 9 that some reviewers gave it, nor was it a 3. I'd say 5-6 overall, about the same as the PS2 game would get.
Despite that, I've had fun with games that didn't score well critically (Deadly Premonition was so bad it was good), and hated some that got rave reviews (I'm looking squarely at FFIII and MW2 right now). It's all subjective. For me, the game is worth owning, but I'll readily admit I'm a fan.
Edit: I liked Yahtzee's review, no fanboy hate on this front, but let's be realistic here. If we all listened to yahtzee's reviews and based our purchases on them, we'd all own the same 8-12 games each, maybe.