I had a setup like this. The IT Office which was its own room, then had 4 of those L cubicles in it.

If you're reading this and you have this setup - don't take the bait to move to the newly remodeled building - it's a trap!

Having worked in one of these, we found those sorts of "team offices" hurt collaboration and innovation even more than open floor plans. Unless the company is pretty small, the random conversations between people from different teams is often the key to innovation and getting problems solved early. A team room means that to ask a co-worker on another team a simple question or to just see what they are working on becomes a big deal because you are now entering that other team's space and interrupting a dozen people. Unless you really know the other person well, we found people just are hesitant to do it.

In big companies, there usually isn't a problem with communicating within a team - the problems occur when teams aren't communicating with people in other teams. These team rooms ruin any informal inter-team collaboration and communication.

My past office was just like that. 10-20 people per room, but usually less than that because people worked from home. Sometimes more than one team per room, because there where smaller teams. My room had 3 teams but we worked in a similar area, so we could bounce ideas with other team members.

It's not a good middle, it's the best possible way to work.

I had something vaguely similar at an internship. Each team was in a separate room for security reasons (aerospace firm), so the co. was all groups of 6-10 people in little open-plan offices. I thought that was nice and quiet.

Team offices are the best in my view. You actually can collaborate there without bothering other people.