I finally caught it yesterday and I really enjoyed it. It really feels like they figured something out as far as the sort of "voice of the show" goes. I ultimately liked season 1, but was a little on the luke warm side because it just felt like there was too much clutter. I don't remember who said it above, but I am super psyched that they cleared up the whole mob power struggle. I think that will clear things up and improve the focus of the show a great deal. It should be noted that I know nothing about the comics and the canon of it all, but as someone who has no reference and thus no ability to be disappointed by them changing things and screwing them up I'm excited to see where this whole "crime team" business goes. It looks like things are going to be really fun this season.
As far as the show stacking against Arrow, Flash and Shield, I think that at its best it is on par with Arrow and the Flash but factoring in consistency I think those shows are better. To qualify, Arrow is my favorite of the shows, and I could see Flash falling behind this year (I'm not sure why, just a feeling but I'm just not as excited for its return as I thought I would be). Given the direction they may be heading I think it could make for some interesting competition. Gotham is better than Shield (though I will credit Shield with improving, but it's still kind of a "meh" show in my book and truth be told as much as I did have fun watching season 2 I doubt I'll be watching it going forward unless I get curious and binge a bunch of it during a slower period like I did last year).