Just finished my first shoot on the LF.
Used the K35 Canon re-housed lenses on this job. Many of them open up to T1.3 and cover the FF, so you can really get some drop off if you want to (although they get a bit mushy there). The images were lovely. It's also less noisy at higher ISO-settings than a smaller Mini or SXT, so a good choice for night stuff. Uses a lot of power though, and it's a very heavy camera, so that's a detriment.
That said, the director complained that on some of the closer shots, it was almost too much drop off. He said, "the background looks comped in, like we shot it on green screen or something". So had to stop down a little more, to around T4-5.6 for some of these closer shots to satisfy him. Which kind defies the purpose of having such a large format. I was on the fence - I saw his point as valid, but still liked the shallow DOF it produced. I could have gone either way.
What wasn't in contention is how lovely it is to have a hint of drop off on even wider images. Even in mediums and full body shots, you could see a light drop-off in focus in background, which is nice to have. Gives it that medium format vibe, which is almost impossible to achieve on super 35 sized chips.
I'd love to use it again, and I will, but for the right project (not handheld). Also, there's a lack of lenses still, unless you want super clean, crisp Zeiss stuff. The eco-system we have with vintage and funky lenses for the smaller formats, is still going to dominate the scene I think until more old lenses have been converted to this larger format.