Parker and Castle Rock are like that with the old MV lamps that IREA equipped for the little neighborhood square fixture pole fixtures, they are changing those over to LED one at a time as the MV goes EoL or people call em in for replacement.  They will eventually get to all the EoL fixtures.. within a few years I suppose.. Unless someone calls them in, which is what I have to do in my community (Highlands Ranch) But now that all the major streets like Quebec, University, Lincoln, Colorado Blvd, Highlands Ranch Parkway and what not out here are converted to LED, it's just the neighborhood fixtures that I call in for EoL or Day Burners.  Nobody bothers to call them in so a day burner can go on for years.  Even those high mast HPS fixtures along I-25 are let go for long periods of time before they get to it.  Very frustrating. 

@RyanF40T12:
oh yep, Parker still has the same MV fixtures in neighborhoods too. guess it must be an IREA thing. I always liked seeing the MV in those places...it just looks nicer to me.
Where Xcel went HPS (actually it'd be 'Public Service' at the time the actual time the MV/HPS conversion took place)

I did notice a few seemingly randomly placed LEDs mixed in when I was at a relatives house in Parker last year...I had figured they were probably test fixtures, but I guess those must have been EOL replacements?

I did notice the LED conversions along some of those roads you mentioned in Highlands Ranch when I went after-Christmas clearance shopping(for lights, what else ) at some stores there.
You'd think they would keep up the lights along I-25, but like you say they don't do the best job with it LOL.

I've seen EOL HPS's out where I live where sometimes they're replaced fairly quickly, other times they stay that way for months... I always figured the county occasionally came around & checked (at the time I didn't know Xcel took care of the lights, its only a couple years ago I found that out).