Man oh man, you have got to get a scaler. I use the Quadscan Elite. It is a little squirrelly to set up, but it is set and forget. It was an incredible improvement.
High lumens are much more important than you would think, if you haven't seen one. It allows a much better contrast ratio. All that theoretical stuff about the blackest blacks is pretty academic when you can double your contrast ratio by making the blackest black 1 lumen instead of two. Your teeth will reflect enough light to wash that black level out. The perceivable contrast ration will depend on how bright the brightest whites are and how much lumen range you have between you ambient light floor and the hot whites. High lumens are critical to shadow detail in my experience. PLUS color saturation and differentiation is greatly improved. Most people that see a well set up high lumen projector are shocked. And if you don't want to sit in the complete darkness to watch sports or paint your room black, you will really appreaciate the flexibility. Still, the darker the room the better it will look. You better take a look at a high lumen set-up before you buy. Also I think Sanyo MLA for LCD and their high contrast technology is still the cutting edge at this point.