Considering the projector is about average in brightness - shy of 500 lumens when best setup for movie watching, the HC6000 is best with small and medium sized screens. No one should have a problem with a 110" screen, but my 128" Firehawk was a little too big for it. Now, my position is that you can use a larger screen if your walls are, compared with off white walls. So you can probably take the HC6000 up into the 120" diagonal range if you have a room with the darker walls, etc.
Now, to screen surfaces. The HC6000 has the improved black levels and that means you can get very nice results with a white surface, something with light gain, 1.1 to 1.4, such as the Stewart Studiotek 130, the Carada Brilliant White or other similar screens. The positive gain, gives you that little extra muscle for the larger screens too.
I, however spent most of my time viewing the HC6000 on my Firehawk G3, which is a light gray high contrast surface, and it looked great. I did keep the image size, though, to slightly over 106" diagonal, and that was a good match.