TubeNet

They're fine. They're sure nicer looking than a case, and the ability to move the padding around to fit different tubas (within limits) is a big advantage.

I ended up deciding that for bulk, I might as well use an MTS case and have the full protection of a hard case. I eventually took to calling it a "case" rather than a bag. But there is no doubt that it is better protection than a lot of gig bags. And it is also more stable than most cases as they come from the factory.

But bloke showed me something when I was last at his place for something else that I think I'm going to do (or pay him to do) to my hard case that will equalize the stability issue.

I am quite happy with mine. The only drawback to me is the size - it is a bit longer (taller) than the MTS for the same horn, and my main rehearsal building has a lot of small hallways and tight corners and doors to navigate. But that's not anyone's fault but the architect. Fantastic stability and tons of storage, though the storage pockets are a bit cavernous. Good problem to have I suppose, but some sort of organizer pouches or flaps would be nice. As they are you end up bobbing for mouthpieces/oil a bit.