I can of course bang my head with Sprint support, but I'm pretty sure it's not the phone.
Looking back only a couple pages in this thread http://s4gru.com/index.php?/topic/2172-network-visionlte-colorado-market-denvercolo-springsfort-collinspueblogrand-jct/page-161
I see that I am not the only one in what appears to be an almost completely LTE-free zone on the west side of the metro area (Colfax, 6th Ave, Alameda, Simms.. generally whole Lakewood area and then some).
Where is one of those new LTE sites in Golden? I'll drive up to one of the towers and check if I have to. I used to have great band 25 coverage there all through downtown Golden, all the way up on Mt. Zion (the one with the "M" on it), and south past the justice center, all the way to the soccer fields at I-70 and C470. Now it's all gone.
[edit]I did just see something I've never seen before. Forced LTE at home, near Green Mtn, and got 1 bar on band 25 (tells me the band 25 radio is working at least, so can't blame the Golden issue on the hardware). I'm often very close to the tower it claims it's connected to, and it has never chosen LTE on its own there.