That was pretty good. The song is well-written and catchy.
I think the trumpets and strings conflict with each other a bit. They feel like they're pulling the song in different artistic directions.
I'd cut a lot of the instrumentation out from the beginning. With the full band fading in like that, it kind of sounds like we're starting from the middle of the song instead of the beginning. Plus, leaving some instruments out at the beginning gives you some room to build later on.
I think I heard some distortion and sibalance on the vocals throughout. I'm not sure if that's a recording issue or a "streaming mp3s through mediocre headphones" issue, but it's worth looking in to.
Overall, it's a good song. The large band blues sound isn't one that I've heard a lot of.