My impression of it was more of a secret meeting place for a hush-hush organization/club.

It sound like a meeting place for cooking club in TS3 Showtime?

I'm playing Twinbrook for my legacy right now, super excited to think of all the evil mutant plots I could make

Do you guys have any pictures of the roads being blocked off ? Because when I go to my Twinbrook, all the roads just end. No roadblocks or anything.. & I really wanna' see them !

Also, I think my favorite house is that farmhouse that caught on fire, but the Sims live in the barn haha. Its so eerie seeing the remains of the old house that burnt down. (:

The fog is also super duper epic.

I am in the process of creating dungeons for Twinbrook. Right now, I am working on the abandoned railroad house near the science lab. The parts (separate tombs if you will) of the place are as follows:
Abandoned Warehouse-search the original building EA made for a switch that reveals the stairs to the basement floors that are being made by me and will contain the other three parts.
Tycoon's Bathouse-enter a place where the railroad tycoons of old relieved themselves and bathed and reveal the secrets of the grimy toilets.
Black Market HQ-reveal the secrets of the black market that once operated here during the railroad days as you explore their dusty HQ and solve their security puzzles.
Fuel Silos-the very smell of this rusty place proves that volatile fuels were stored in the two silos here during the railroad days.

Twinbrook is such an interesting town with a lot of history, so it deserves to have dungeons in it that serve as reminders of its past.

Twinbrook is not quarantined. You can find the exit/entry along the Pidgin Mansion. What I found strange is that beyond the town proper, the road changes from concrete to dirt-road. I'll post a picture when I get home.

If Twinbrook was a location in the game Might and Magic VII, I would give it these monsters:
Sprite, Sylph, Water Elemental (these would appear in the ocean, in the central lake, and in the rivers)
Rotted Corpse, Walking Dead, Zombie (these would appear in the swamps, in the yellow spots, and around the graveyard)
Wight, Wraith, Barrow Wight (these would appear in the swamps, in the yellow spots, and around the graveyard)
Titan, Storm Titan, Blood Titan (these would appear in the farm fields with the impact craters and around the amphitheater)
Titans, Storm Titans, and Blood Titans are very strong and would be somewhat few in number in their areas. I have a link to a video on youtube made by someone else below here that shows just how lethal a Blood Titan is. Watch as the Blood Titan kills the entire party of the video's author at one point.
Be afraid, be VERY afraid of the MIGHTY Blood Titan!
In terms of the fictional Innsmouth, the Water Elemental class of enemies represents the Deep Ones and the Titan class of enemies represents the Old Gods. The Wight class of enemies and the Zombie class of enemies represent the ghosts of Twinbrook.

I just downloaded Ambitions and Late Night *I'm still building my expansion packs, been playing TS# for about 4 months, but I'm a longtime simmer* NEVER in my entire Sim career have I played poor sims.....and then I got a look at Twinbrook.

I created a sim, Moira Duffy, and moved her eccentric, wanna-be DaVinci butt out to to the swamp, right across from the sludge pouring out into the swamp. I had noticed the sickly looking sims, and immediately decided that TB was an earlier Strangetown...that an industrial disaster has happened, and the the MUTATION was well under way. This mutation, and the irresistible need to investigate, will eventually bring aliens...who will cross breed the various mutant types with their own DNA until we get to the alien/mutant types found in Strangetown.

I may just have to throw in some Zombies, just to get all "Walking Dead" with it.

There is a fan-made game called Mushroom Kingdom Fusion out there. The video below shows its fifth world, Gehenna. Considering the nature of Twinbrook (and the way its sky looks sometimes,) I wonder if it would make a good level for Mushroom Kingdom Fusion's Gehenna.
Link to the video on Youtube.

For me, I think that SV was Pleasantview before a disaster forced people to leave, and that Twinbrook has a high likelihood of the same stuff happening. I'm thinking with Twinbrook, something like Under the Dome or The Crazies, and with SV probably it was abandoned. With SV . . . I don't know, something about it strikes me as too perfect, like it's standing on shaky ground.

Some of you guys seem to be making your Twinbrook well on its way to post-apocalyptic, if you really want a post-apocalyptic world, come join my Community project (the link is in my Signature)