I have not seen the piano, so I have to compare with the lt150z. IMO the lt150z looks better than the AE, and screendoor is not in the same league. The difference however is very small if you can sit far enough away from the ae to stop seeing screendoor. I think the reason the lt150 wins out is because of slightly better blacks, a lot of AE100 owners are using filters to improve this.
In the US, definitelly not worth the extra money for the lt150z unless you can't sit far enough from the AE to avoid screendoor. If price is not an issue (Ive heard that the AE ends up being quite a bit more expensive in europe) then check for rainbows and act acordingly. The AE is a perfect entry level pj, definitelly Wow factor, 5000hour low cost bulbs, relativelly quiet, good colors, decent blacks and no rainbow problems.
Watched Run lola run (blah with a good soundscore), Wet Hot American Summer (in the monty python, southpark tradition), Sliding Doors, The Matrix (again after trying to improve the color settings) Xfiles Fight the Future. As usual I love the gamma correction of the cinema mode for regular movies, but it is still too much for the Matrix or Xbox games (normal and dynamic) What this means is that I am going to give up on the Video Essentials dvd and buy the Avia this week. 187 hours and counting.