They are awesome but not as a key. Not enough output, really, unless you gang up many many panels. I use them to fill in holes, fake a window, light spaces like closets and refrigerators and car interiors.
As TMark said using Kinos or any florescent is too dim for a key for stills, also for most video unless you use the 5d2 at about iso 2000 (which is pretty smooth for that iso).
Also all the florescent fixtures produce a fairly soft light and other than softer modifiers don't offer much in the way of flexibility.
I have the fotoflex, (the ones with the huge bulbs and also another brand (don't remember at this moment) with smaller florescent bulbs and they both put out the same output, or close to it, regardless of the specs.
One upside to the fotoflex kits are they take daylight florescent and tungsten bulbs. The tungsten put out a lot more light.
So bottom line if your shooting a combination still and video project, don't expect to take your low iso medium format back and freeze a moving subject, unless your use some very heavy duty hmi's (which on location have to be spiked into the breaker box) or run a very larger generator.
If you can live with 800 iso at F 5.6 with a dslr, then you can use most any continuous source but you still won't be able to freeze someone jumping in the air unless you use a D3s at iso twenty billion.
Personally, I like tungsten with digital and believe it gives a nice look, is cost effective, and you can buy a lot of arri tungsten for the price of a decent hmi and ballast. As far as grip, it depends on what you shoot. Obviously modifiers for hot lights and more complicated with 4x scrims and a lot of flags to do pretty much what one beauty dish will produce on strobe, so if your working on budget and can't afford a gaffer, be prepared for a medium learning curve and get some hot gloves so you can keep your fingers intact.
If your working any sized project with a budget search out a good gaffer that has his own truck and equipment. They will usually work very favorable package deals, they know their own equipment well and though there is a time delay, it's not off the wall long if the gaffer and grips are good.
I agree with gwitif that profoto, bron or someone should make a more cost effective hmi, cause 5 grand for 500 watts just doesn't do much. Maybe it they were 1,000 watts you could swing it (though still on the limit), but 500 watts can be limiting and in medium format land you better get one of those old timey head braces to hold your subject still.
One trick I do when shooting continuous for video and flash for still is to set the lights for continuous and then add a small monoblock, usually as a very turned down backlight through a soft modifier like a shoot through umbrella. This will help freeze the subject on stills, not really interfere with the look of the shoot on video and though on stills you might get some shutter drag blur, usually it's sharp.
Regardless, with a combination still and video project your pretty much in dslr territory, if there is movement.
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BC
