In terms of putting one of these VW600ES projectors in your home theater, the good news is you really have more than enough brightness, at least in 2D, for movie watching on typical screens up to at least 150" diagonal.
Think of it this way, for the same brightness you would find in a typical movie theater (12-16 ft lamberts), you need around 400 lumens with a typical 1.1 gain screen that is 100 inches diagonal.
Since the VPL-VW600ES has about four times the brightness - post calibration, we can quickly interpolate that it should be able to handle a screen size of up to 200" diagonal while producing it's best possible picture. That should make it the darling of many hollywood directors, cinema-photographers, etc., for their home screening rooms - which are typically a magnitude larger than the home theater screens we mere mortals own.
As always, there's always the issue of 3D, as you always give up more than half and more typically about 2/3rds of 2D brightness. Now few people will have two different sized screens; one for 2D and a larger one for 3D. Most of us therefore settle for not quite as bright as we would like when viewing 3D, because we're filling the same sized screen.
Of course, with a projector that has lens memory, as this Sony projector does, there's nothing to stop an owner from creating a smaller projected image for use with 3D, that can be accessed at the touch of a button on the remote control. And of course, if you go a step further, you could have a masking system that would mask the visible screen size down to the size of your 3D projection.
When watching other content, the Sony may not be much brighter than it is calibrated, but it still qualifies as a light canon. Now the rich and famous can put one of these in a non-home theater environment, such as a less than well light controlled family room or bonus, or media, or living room. For those that can afford, why not, after all, part of the reason for owning this VW600ES is the gorgeous 4K output. Why not have a super sharp 4K projector in your media room? Soon enough we'll start seeing 4K coming in over satellite, cable and broadcast. Certainly I'd much rather watch my NFL football in true 4K or Ultra-HD whatever you prefer to call it, than in 1080i - who wouldn't.
And that's fine, because the VPL-VW600ES does put up over 1700 lumens at maximum, and the picture still looks pretty great, if not as perfect as as the not much less bright calibrated mode.
When you look around the market, any projector that can put noticeably more than 2000 lumens on the screen fits into one of two categories. Home entertainment projectors which really aren't remotely comparable and mostly under $1500, and super expensive high brightness projectors from the real high end companies, such as SIM2 and Runco. Of course most of those much brighter projectors, cost $30,000 to $100,000+ and are still only 1080p resolution.
In other words, short of dropping an amount of cash on your next projector that makes this Sony seem downright inexpensive, nothing serious really is significantly brighter.
End of conversation on brightness.