without going into too much depth...HA! 
i hereby cast my vote with the following reasoning. Firstly, i was never going to be drawn to any "realism" in this challenge i.e the HDRI images which although stunning and creative, were still inside the box too much for me. sorry but at least i am reasoning out my votes. the challenge subject was inspired coming at the time of bryce 6, and i hope all you brycers are ashamed of yourselves using up all that electricity and shortening the lifespan of our planet by about 5.7 years, just to render  a decent glass image.:)
brilliant entries all round and after visiting, making a shortlist, re-visiting, making another shortlist re-re visiting, i vote as follows:
savantnoir- 3 points  - shoot me i like symmetry and clear cut definition, this was beautiful!
Paul Francis - 2 points- paul rightly gave credit to the ministry scene he used , but he made this image exceptional without overdoing it. and just far enough  outside the box for my tastes!
Aeello -1 point - although similar to orbitals entry in subject matter, this one edged it for me because it was a true "bryce" image which followed the brief. dominant glass as the subject and...yup, shoot me again. a bryce sky being reflected! well i liked it. 
honourable mentions to boekenwuurm (yer killin the planet with those 23 hour renders man! lol) and Agent smith (keep it up kid, you might just get somewhere :))
 a wee bit disturbed to see a flurry of votes for a first time entrant who shall be nameless . its not about voting for yer pals guys its about being subjective.

like others before me, i doubt my votes will change the two horse race and congratulations to the eventual winner because the standard of entries was superb