Why I think GTA IV and GTA V don't really have a winner:
When Rockstar made GTA IV they started over from scratch. A lot of people complain about GTA IV being dull and boring and not having enough stuff to do, but look at the only equivalent GTA game ever made: GTA III. GTA III had one of the worst stories in gaming history because there was no main character, the driving was atrocious and the lock-on feature was more likely to target grandmothers than the person you actually wanted to aim at. Despite that, it gets a lot of passes for being the first 3D GTA game and if it wasn't for the way it combined its features together, GTA III would have been a largely forgettable experience. GTA IV, likewise, does not have all of the features of San Andreas. A lot more time was spent on developing the world and the graphics because we are now dealing with an HD generation that requires a certain level of graphical quality. Sure we can say stuff like Minecraft proves the opposite, but stuff like Minecraft are in the minority.
GTA IV is a remarkable step forward for the franchise in that everything it decided to do was remarkably well done and put together. The driving was unique for open-world games, though a bit too slippery perhaps, the shooting was a step forward with a cover mechanic that matched other games of the time, there was a nice variety of weapons that they had redesigned that all felt really good to shoot, they had a variety of interiors that one could go into at any point in time, you could buy food from any vendor, there were a good handful of clothing options (more than Vice City), full bowling and pool games that were very well put together, and a small handful of things to do on the side and TONS of small detail.
That said, GTA IV's story was written to be realistic almost at the expense of pacing. Niko immediately dropping his hunt for the mystery individual to help his cousin out with his cousin's problems, which only gets them dragged further down into the criminal underworld. This stuff could have been handled perhaps a little better, but this was Rockstar's first attempt at anything other than ripping off popular movies or outright parodying something. The story also goes on a bit too long, Niko always finding ways to do something for someone rather than really going anywhere or doing anything. The dating and friend mechanic was well implemented (IMO better than the properties in GTA V) but there was way too harsh a penalty for saying no without first saying yes. Taxi missions were also locked off for no reason permanently and some discrepancies between the map and the story truly boggle the mind at times (where is Roman's 2nd cab depot!?)
Despite its issues in story and pacing, there is really few issues that I can find with the stuff they did add. Vigilante was a very good step away from the horrible way Rockstar had been doing vehicle side-missions. No longer were we confined to a car for 12 levels but instead we could get out and we had several baddies to hunt as well as random crimes to stop. Vendors worked wonderfully and there were plenty to find around the city. The interiors added a splash of life and I loved having firefights in them. The city itself looked beautiful and felt like a real place I could go visit... if I had a death wish. Bowling, Pool, and Darts were fun and well put together. The shows you could view were fun, although perhaps they should have stuck to radio skits in order to keep us playing the game. There was such polish to the little stuff they added that it felt like a new route for the entire Rockstar company, doubly so when the remarkable Red Dead Redemption was released.
GTA V, on the other hand, is a much less polished feeling game. I'd downright say the base of the game feels unfinished, half-tested, and rushed. The way you get wanted too easily, the way the cops have razor sharp vision to the point where I have been one-hit-killed several times from full health (no armor). Getting rid of a 4 star wanted level is extremely difficult, yet in contrast 1-3 stars are basically too easy. Health regeneration is a joke and often times doesn't work or doesn't help in the slightest. Where they got health so right in Red Dead they made a bastardized child by mixing it with GTA IV's health system. Driving is subjective, so I won't comment on that but vehicle damage is completely gone from GTA V. No I don't mean the physical damage which is still in place and arguably better/worse. I mean the fact that cars no longer sputter out and die on you. Instead helicopters sputter and die on you. Cars just explode without warning or keep running like energizer bunnies.
We lost vigilante and we got Bounty Hunting. Except instead of 30 most-wanted and random crimes we now get 5 guys to find and ... that's it.
We gained taxi and tow trucking.
We lost many interiors that they could have copy/pasted to save time.
We lost street vendors in a game where they should have been plentiful to help us get above half-health.
We still have races and now they are in several varieties. I don't give them any credit for that though because that's the least they could do in five years of work... you know.. improve something.
We have properties which now serve the purpose of being the "Roman" of GTA V. So many stupid text messages over and over while I just want to explore. LEAVE ME ALONE! GTA 4 wasn't half as annoying to me. These properties also are half-baked. We can't go inside most of them and they give a ridiculously low return on our investment. Most side-missions for them are introduced via a text message. Vice City did it better and that was made in a year on the PS2.
We can't grab ledges anymore but hey we can ragdoll at will. Funny at first but gets old.
We lose car theft sidequest, which they could have easily fit into GTA V.
We have 10 missions for one property which consist of smuggling weapons out of the country... that's fine except we don't get anything for it unless we repeat it over and over.
GTA V is a lot of fun, but it feels conflicted. For everything it does right, there are a bunch of small wrongs that tickle at the back of my mind and pull me out of the experience. It by no means ever takes a full step back from what they accomplished with GTA IV but nothing it does truly surpasses it for me either. If I had to summarize my feelings on GTA V: When painting their new masterpiece, Rockstar spent too much time redoing things they had right the first time and focused far too much on the small details that it seems they missed the big picture.