I get that it sucks but couldn't you have just looked at LTE coverage maps for pretty much any carrier before buying? Or at least went to an Apple Store near your location and run Speedtest? I'm not trying to call you out, I'm just wondering if those two options were available to you before you bought this.
Where are you in Denver? I was just there this past weekend and had a great experience on my AT&T iP5 with LTE. I was streaming spotify on LTE in the NW and along the airport corridor of I-70
I live in Denver but in central Denver and work near downtown. I have AT&T on my iPhone 5 with LTE and get great signal. But I am getting a Verizon Mini this weekend because:
1) Verizon has better priced data (I am grandfathered unlimited on my iPhone and don't want shared),
2) Verizon offers hotspot on all data plans (AT&T only offers it on their highest iPad plan), and
3) Verizon from what I have heard has much better and more extensive LTE coverage in the mountain corridor and throughout the ski towns.