I don't see how these aren't "controllable."
I'm planning on getting a diffuser for the one light without the umbrella and I can get dimmers.
You'll see what I mean if you visit a film set or use any of the common location lights. Barn doors (used to direct light), scrims (used to stop down light), focus knobs (used to control spill quality), and interchangeable lenses are all common features.
I'd avoid using dimmers as you'll encounter what's called "amber shift". if you have any dimmers in your house, I'm sure you're familiar with it. Specifically, it's the tendency for all filament-based light sources to emit warmer light when they're dimmed. By using scrims (metal screen discs), you cut down the light and avoid any temperature variability. Not to say worklights are any more accommodating to scrims, but both options will require rigging up some DIY magic.
I guess what I'm trying to show you is that these lights will require you buying a bunch of stuff anyway... might as well spend less money to get more powerful, more durable, more sturdy lights and then have more money left over to buy the things you need anyway like diffusion or bounce boards.
Those lights look cool, but without real control, your picture's going to suffer.
EDIT: I should mention that I don't like using lighting at all. I prefer realism over cinematic imagery, and avoid the hassle almost completely. Artificial lighting is becoming less and less necessary with video chips becoming more and more sensitive. Whether or not to enter that entire realm is up to you, and is usually the only choice if you're going for a specific, dramatic look.