Actually I'm not sure i like the idea that they all live together. In TMM they all had separate lives. Everywhere you turned there was a muppet leading a regular (sort of) life. In GMC Piggy, Kermit, Fozzie, and Gonzo all lead separate lives. Kermit, Fozzie, and Gonzo only lived with the rest of the muppets temporarily in the Happiness Hotel. In MTM they all lead separate lives outside of the band, Kermit, Gonzo, Fozzie, and Piggy and Scooter. They lived in lockers, but they had separate backgrounds. They met in college and the rest of the gang was spread across the country. It wasn't until MFS that the idea they all lived together full time came about.
So if i had to choose I guess I would much rather an apartment building. Each has a separate space, but in the future I'd like to see something more like GMC where they don't just all know each other.