About the Sanyo's brightness...
I had a slight concern that it might project too bright a night-time image. Fortunately, I can report this is not the case. Anyway, I feel the picture looks best with the room lights dimmed low, but definitely not off. Other users have made the same comment. The brightness pays off during the day, but you should still draw the blinds if you're doing any "serious" viewing.
The light reflected off of the projection surface illuminates the entire room significantly, even in a big living room. However, I want to experiment with a filter to drop the black-levels since the projector's brightness will still enable it to produce nice bright whites.
On the LT155...
I've stated before that if portability was a key factor in my decision, I probably wouldn't look any further than this guy. The picture was very smooth, with almost no evidence of doubling/scaling errors. This is sigificant since it was fed from an inexpensive Creative Labs DVD decoder card that isn't nearly in the same league as a good standalone machine (my interconnects cost more)! On the other hand, brightness, contrast, and saturation left me wanting for more... but it was still impressive performance. Its color fidelity was good, and was almost pefectly calibrated right out of the box. The Sanyo required serious tweaking with respect to hue and saturation.
I should qualify all of this by stating that I am NOT using a projection screen at the moment, just a white wall with black felt masking. (The masking is key for ANY widescreen flic.) When I install a proper screen in the next month or so, Stewart's Grayhawk sounds like a no-brainer. I plan on buying raw material and constructing my own frame. Apparently, this screen material will milk a lot more performance out of any digital projector. A white wall does not do a good job producing the illusion of depth.