Anton the umbrella I saw was a bit flatter and maybe the one you showed me was adjustable, I'm thrilled by it's being parabolic though.
When I was filming commercials I used a lot of umbrellas and light boxes which were used with studio lights (not strobes or flashes) up to about 6 feet across, they all worked as tools for various projects, I also used silks, muslins, of various densities in sizes running from 4'x4' up to 20'x20' with every kind of studio light imaginable behind them, sometimes shooting directly through sometimes bounced off sheets of 4'x8' foamcore and then let that light come through the silks, often we used 12'x12' frames stretched with black duvoteen to cut the light and make them into huge light boxes. We also used huge light boxes overhead which you could get big enough to cover a car and then some, they would move up and down from ropes and pulley's attached to the grid overhead. I used to take breakdown overhead light boxes which were 2'x8' made of aluminum frames and foam core and we'd tape them together and cover the open panel with 1000H tracing paper, they would have tota lights inside and be placed overhead, in front horizontally or vertically it didn't matter but it was before Chimera and others started making anything of any size.
I also used what we called a Bob and Greg light because they were the ones who created a snoot about 3' long with diffusion spaced at 3 different intervals along the inside which was white foam core and the front had a black snoot like a large lens shade on a telephoto and behind all of this was a 2000 watt light, I'd use it in certain table top circumstances and even on a face as a key or kick light in low key (darker background) circumstances. It worked really well, and they also made me one that that was one unit over another so it could telescope, it created a very localized but very soft source.
It all depends upon the nature and size of what you want affected by the light. Light is simply a source, whether pin point like the sun or broad and gentle, it's up to you to change it to create the affect you want.
What I'm getting at is to use anything that works, there really isn't an either or scenario unless one method can only look ugly no matter what you do and then you really should try something else.
Some photographers I knew carried bolts of white silk to put the light through when filming womens faces, I've done that, it's nice, I've also used banks of flourescents, like with 8-4' color balanced bulbs shot through one of the Lee or Rosco diffusion gels on an actresses face when the space we were shooting in did not allow for larger equipment but I wanted it to look like a very soft window light, all that could be set up in an area with the talent only 4' from a wall with the light inbetween somewhere. If it works and looks beautiful then the method's justified. Don't limit yourself!
When flying in to a location years ago in Alaska, we'd carry a kit with 9 tota lights and stack them one on top of another, then for interiors we'd have small exension cords running to every outlet that would handle them and the light might be bounced off a soft reflector which then went through a large sheet of spinnaker material to get a simalar look to what I was talking about above. It's all source and manipulation, the important thing is to experiment and learn to see when you can make a difference lighting wise in the immediate circumstances for the best available with what you have to work with.
Yeah, I've also done this in a farmhouse with a king sized bedsheet and then the next shot over to taping the sheet to a window where the sun was coming harshly into a bank and shot the interiors using soft reflectors in the bank bouncing back the light from the sheet and ended up with very nice results. That very same day we got some huge sheets of cardboard in this small farm town, had people hold them up and draped the bedsheet over them to serve as a soft fill light outside while shooting a farmer at work in back lit sun. It's all fun!
Once you have a source of light, you can do a lot with your imagination.
