Would you even call it a sequel ? Its liberty city again, albeit with a face job. But the fundamental gameplay is identikit to how it was the first time we touched down in GTA3.
Yes I haven't spent that much time on it, and the world is probably a lot more fleshed out, and there are some subtle nuances and improvements carried over from San Andrea's etc... but enough to say 'a breath of fresh air' ? Well IMHO no, what we haave is a basic refinement of a recipe they have served up already.
It does not feel new, it feels like re-visiting the old more than reveling in the new. That's not to say the game isn't fun or enjoyable which at the end of the day is probably the main factor, but for something that 'breaks the mould' like GTA3 first did, you really need to look elsewhere. This is rockstar playing UBER safe with a franchise.
It'll sell well, it'll win awards.... Doesn't stop it being fundamentally a rehash.