We used the equivalent of a 35mm sensor on Angry Planet and Alien Insurrection using a Letus camera adapter. Oh, and Clonehunter.
But starting with Day II we've been using a micro 4/3rds format camera. At first it was the GH1 and now the GH3. We save a lot of weight on the camera rig by not having that Letus adapter (although that adapter does look nice, I kinda like everything Letus does.)
The micro 4/3rds is bigger than Super-16 but not as big as 35. But you know what? It's big enough. You open that puppy all the way to f2.8 with a long lens and you have some nice softness in your background. And also it isn't a bear to focus. It's kind of the best of both worlds.
Thing is, with the micro 4/3rds cameras we now have to contend with rolling shutter.
You see a bunch of tests on the Internet showing the skewing that rolling shutter does. And, for instance, on my brother's camera footage from his quad copter you can see the propellers "bend" from the rolling shutter.
But for most practical situations you just never see the rolling shutter. Even in hand-held fight scenes with whip pans the issue of the rolling shutter seldom makes itself apparent to the naked eye. Yeah, if you freeze a frame you can see that vertical lines are bendy. But other than that, who really cares?
Well, I'll tell ya, you care when you go to do a composite with a handheld camera. On the GH1 we learned (after struggling in post with the GH1) to be very careful when compositing in a background on a handheld shot. So we started being very religious about locking down the camera when we were going to be compositing (say) giant robots in the background.
When I realized this I started jonesing for a (somewhat) large-sensor camera with a global shutter.
The other significant issue with the GH1 was the way the blacks got very noisy in low-contrast environments. This causes these obnoxious horizontal bands across the screen that are impossible to get rid of.
So we moved up to the GH3 with a single f2.8 zoom (uh, 14mm to 35?) The GH3 has improved on that noise in the blacks (which was dinging us in QC) but also behaves better as far as rolling shutter artifacts are concerned. I have no idea what magic the engineers at Panasonic are doing but it's rather magical.
In any case, it seems we have a much easier time doing composites with handheld shots. And that's really almost all I care about.
Here's a video of footage from the GH4. The GH4 is a 4K camera. I don't really care about 4K. Nobody else does either.
But there's a lot of nice motion without (what I can see at least) a lot of rolling shutter artifacts.