I played the original Mafia on the PC, and frankly from the review it sounds like Mafia 2 is very much in its predecessor's footsteps. Which is to say, it's not Grand Theft Auto. That's not necessarily a bad thing. The GTA games have always made big play of the whole "sandbox world" thing, and it's true, there's a lot of stuff to do and often several ways to do it (I was tickled to discover it was possible to easily complete a "motorcycle" mission in one of them very easily by using a helicopter...) but if you think about it, character, plot, and plausibility often fall by the wayside in the name of doing so. There's often little more reason for the protaganist to be engaging in the various activities other than that, hey, there's a mission flag or a race flag or an activity flag in this particular spot. Don't get me wrong, I've really enjoyed the GTA games I've played. They're very entertaining, they're just often entertaining at the cost of having a big neon sign on their chest that says "this is an entertainment".
Mafia (the first one) looked superficially like a GTA clone, but it was significantly different. There was less of a sense that the streets (and cars) bleed into the buildings (and the chases, gunplay, and fighting), but in exchange there was a sense that the various set pieces were being choreographed and shot by a skilled director rather than largely improvised by an amateur psychopath (that being the player, no offense.) Having to drive from one end of town to the other in a car from the 20s that could barely reach 60 mph around cops who actually paid attention did more for my sense of "I'm in a real place" than all the rushing around on sidewalks and over bridge rails in GTA, entertaining as they were.
In short, I'd still go ahead and buy Mafia 2, or at least read around for some more reviews rather than insisting one feature set is the be-all-end-all of what a game of this broad genre must contain. It's a different experience, but not at all necessarily an inferior one.