I don't think it is. It misses out a bunch of features and mission variety.
I think a lot of us who played GTA 4 know that the missions can be repetitive. And not just drive to point A to point B deal. It's the presentation and the heavy scripted car chase scenes. It's too much. It's predecessor had less scripted car chase scenes where you can kill the driver, police chase you, or any other random thing could happen. They all too familary presentation of going driving to point A to point B to a warehouse or field or something to kill somebody. They never add anything too different. You were basically a hit man throughout the game.
Granted, Ballad of Gay Tony DLC added some cool missions.
2. Nothing to spend your money on
GTA 4 lacked here in comparison to Vice City, San Andreas, and GTA 5. While you could spend your money on clothes and guns, you are just restricted to that alone. In all the games that I mentioned, you can do that and buy properties and businesses. SA and GTA 5 you can customize your car and have more clothes to buy.
Granted, GTA 4 is suppose to be most realistic out of the current GTAs, but still doesn't exclude the lack of stuff that you can't do with your money. You don't have to buy businesses, but car customization and more apartments would've been nice to have seeing as GTA: SA did it before you. Even when I robbed the freakin' bank, my standard of living don't really seem to change much because I don't really have anything to spend it on. Hell, Niko is still looking for work as a hitman. But this leads to my personal dislike of the game.
3. Your standard of living and status don't change much (personal opinion)
Niko throughout the game was a hitman for various of gangstas and some corrupt cops. But imo, you never really feel like you step up the ranks that much. While you do work for the higher organizations and higher boss within that organization, you are basically a hitman. You were always a hitman and nothing more than that. They never even give you benefits for being great hitman. They hardly awknowledge that you were a awesome hitman. There was no moving on up for NIko. Granted, you did go to a different apartments, but I don't recall it was out of your money (correct me if I'm wrong) but it was out of the storyline and Roman's money.
Like with San Andreas, you work your way to the top again of your own gang. With the respect meter, you were able to recruit other gangstas to follow you. You weren't really the leader of the gang, but co-leader I suppose. But at least they awknowledge your hard work. In Vice City you also work your way to the top. Right before you even establish your own gang there, you had major respect of top gangstas there for the work you did for them. The whole game felt like a monotone of working hard to achieve little.
That was something I was missing for GTA 4. Maybe you guys felt differently than me.
Anyway, I do like the storyline and its darker and serious tone of the series. But it misses out a few gameplay features and progression that just make the prior games and GTA 5 very fun. The game itself was both a step forward and a step backwards. It was almost like remake of GTA 3 instead of a advancement of GTA: SA and Vice City. Despite my criticism, it is still a great game. I just don't think it's the best.