Observation Rooms: Be accessible, or inaccessible?
What do you all think? What's your opinion about Observation Rooms being accessible to the player? Do you think it's a good idea or not?
My Work
[spoiler]Maps:
Revenge of the Angry Turrets
Capture the Cube [Co-op]
Capture the Cube 2 [Co-op]
TPWEGTH Sample Map
Aperture Aquatic Testing Center
Aperture Aquatic Testing Center 2
Aperture Time Testing Center
ML's Halloween Trick - 1000 downloads!
ML's Halloween Treat
ML's Combination - 1000 downloads!
ML's Jailbreak Labyrinth
ML's Tricky Teamwork [Co-op]
WIP:
"Capture the Cube 3"
Workshop Maps Link: http://steamcommunity.com/profiles/76561198008890579/myworkshopfiles/[/spoiler]
And in Time Machine Maps they fit too! I like it in your Time Machine Map Masterlagger 
Well, I think there are two reasons why you could access the observation rooms:
1) because there is some irrelevant easter egg.
2) because in that room you can do *something* that will effect your puzzle, but doesn't make sense in a normal test track.
so good example: as in your back in time map, shutting down turret production
other good example: an observation room with a turret guarding the testchamber
bad example: a room where you have to press a button to activate a funnel 
I always tried finding ways into a observation room in both Portal games (usually unsuccessful). ML Combination took Observation Rooms a few steps further but I feel that there could be more done (employee lounges, lobbies, etc) and allow the player more freedom.
My Work
[spoiler]Maps:
Revenge of the Angry Turrets
Capture the Cube [Co-op]
Capture the Cube 2 [Co-op]
TPWEGTH Sample Map
Aperture Aquatic Testing Center
Aperture Aquatic Testing Center 2
Aperture Time Testing Center
ML's Halloween Trick - 1000 downloads!
ML's Halloween Treat
ML's Combination - 1000 downloads!
ML's Jailbreak Labyrinth
ML's Tricky Teamwork [Co-op]
WIP:
"Capture the Cube 3"
Workshop Maps Link: http://steamcommunity.com/profiles/76561198008890579/myworkshopfiles/[/spoiler]
Me like freedom!!!
my bad my bad, geez.
Mapping Since May 21, 2011
my bad my bad, geez.
Didn't aim at your maps o_O it's just my two cents
Yes, that would be nice, but the models for that simply doesn't exist. You could make them though. And well, more freedom is fun, more exploring is fun, but I'm afraid big bts area's where there's nothing to do aren't really worth the trouble, unless you put them in a big mappack/mod.
Use 1940s Aperture models? They look enough modern to use for Clean Aperture.
Pitkakorva is right, some of the Old Aperture models do look modern enough for Clean Aperture.
My Work
[spoiler]Maps:
Revenge of the Angry Turrets
Capture the Cube [Co-op]
Capture the Cube 2 [Co-op]
TPWEGTH Sample Map
Aperture Aquatic Testing Center
Aperture Aquatic Testing Center 2
Aperture Time Testing Center
ML's Halloween Trick - 1000 downloads!
ML's Halloween Treat
ML's Combination - 1000 downloads!
ML's Jailbreak Labyrinth
ML's Tricky Teamwork [Co-op]
WIP:
"Capture the Cube 3"
Workshop Maps Link: http://steamcommunity.com/profiles/76561198008890579/myworkshopfiles/[/spoiler]