So in other words.. TONIGHT!
V definitely improved on some things from IV and was seen as bringing the series back to the gold standard set by SA when it dropped. Driving was better, car customisation was back, stats were back, tattoos, barbers etc were all back
V plot/writing is bad but overall I think the game is an improvement on IV
It's all down to what you're looking for out of a GTA
For me, the writing is paramount, if the characters aren't done well and the world isn't interesting then I don't stick around. And so the writing, for me, outweighs any improvements in graphics, cosmetics and even driving handling to an extent.
Second for me would be the art direction and overall mood. GTA has always been a tour de force in atmosphere, more so than storytelling imo.
I have high hopes GTA VI will fair well in both these aspects.
another day closer...