I always thought it was just 'fine', but in comparison to season 1 it looked like total crap.
I really would like to see how someone who had never watched season 1, or even heard how good it was, would think of s2 in a vacuum. I think they'd still rate it above average, maybe a 6 or 7 out of 10, and then be blown away by s1.
I mean, 95% of the show was good, but the 5% that wasn't REALLY stands out and makes the whole thing feel uneven. The ending was pretty bland, almost pointless, and that can have a huge effect on your opinion of a show. If the rest is amazing and then has a shit ending, it still makes you think the whole movie/tv show was shitty then. Vaughn had some great scenes, and then a bunch where it's obvious he's trying to force it. That's likely due to the uneven writing. McAdams was just.. there. I didn't hate her character and I didn't like her either. The secretly gay dude was boring until the end, at which point I liked where they were going with him, but then it just stopped. Had they focused more on his 'badass-ness' earlier on, might have been a different story.
Overall, it's not a season I'd recommend people to go out of there way to watch, but I kept watching this show each week when it was coming out, so it at least held my attention. If I actually dislike a show, I stop watching pretty quick. This just felt like it had a good start, but was lacking the 'polish' to make it really good. So, hopefully it really just was that the writer was rushed to pump it out and will be given more time in the future.