If you go around the online forums to measure the general feelings on season four, your going to find a consensus on how much this season sucked. I don’t feel as negatively as most online commentators, but it wasn’t a great season.
The main crux of this season focused on a number of things. It focused on Damien Dark, the big bad this season. Dark was really cheesy whereas Ra’s Al Ghul was darker and more menacing. The romance between Oliver and Felicity was really cheesy and just reinforced the idea that this show is on the CW.
The biggest disappointment was that the whole season was about trying to figure out who was in the grave. They showed someone dying in the first episode and the rest of the season was spent throwing red herrings and fake outs about who was going to die. It was such a repeated gimmick that by the end I just didn’t care. You can only watch so many episodes about whose going to die and then getting faked out before you just stop giving a damn.
The side story on the island was also pretty bad. Why is he still on the island? Jeez show runners, realize that you don’t need to keep telling a flashback plot line anymore. Just tell the story in the present. It’s a tired storytelling gimmick.