Gameplay over graphics by a landslide. If the game looked like a ton of fun, I wouldn't care about the graphics at all. They look pretty bland, but they get the job done. The problem is, it doesn't look very interesting to play.
I don't think you're understanding the position of most who are expressing their dissappointment in this game based on the graphics.
For folks here like me, I've been interested in the gameplay from the first announcement. It just sounds like a typcal open world action game gameplay, with TPS and cover mechanics and a mission-based structure. In concept I fail to see how GTA is in anyway significantly different to this game.
This one adds the hacking mechanics, which in concept sounded awesome when first announced, but as of now seem to amount to not much more than "point at object in gameworld and press X to interect". It's not revolutionary, but it adds that little bit more interactivity in terms of game mechanics than others in the genre. So I'm perfectly fine with that. As long as the driving and shooting mechanics are solid it's fine by me.
So, I've focussed on the graphics because that seems like the only part of what they've shown that is dissappointing to me. I'm afraid I don't share you sentiment regarding the gameplay, as I can't see how one could consider this boring and GTA not, since the mechanics are, outside of the hacking element, for the most part fundamentally the same.
I don't see it as an issue of graphics over gameplay because the gameplay is a known quantity that we've all beenfamiliar with from the beginning. It's the graphics that I've been eager to get a closer look at, and now that we have, they're pretty offputting.