I found Nico Bellend and his brother (I forget his name) to be utterly annoying characters, the missions very repetitive, the cover system horrendous - and whilst the map was huge and fantastic it was a lot less interactive than its predecessors. The buildings were all just walls - there were less that you could enter. Sure, eating and working out were nothing but silly diversions in SA, but I missed silly diversions like that in gta4.
And damn but it was glitchy!
Despite all its flaws, I loved it - I just didn't think it anywhere near add good as it should have been. The GTA games have always been a lot better than their predecessors, but I'm not sure 4 was.
I'd be hard pressed to say which is the better, from gta4, sr2, and sleeping dogs. All three were great games. Which is why I say saints row or sleeping dogs could easily usurp GTA's throne if they played their cards right. (Except SR decided to go a different route, unfortunately, with 3 being ridiculous and 4 going even further
).