This is my first experience with the new Second Life(TM) Prohect Viewer: New #SL Project Viewer. Its just a quick look.
Download & Install
The CHUI Project Viewer is the standard download. The file is about 29mb.
The install places the viewer in its own program folder. The viewer has its own settings. So, you will have to run through the settings to get it the way you want.
However, my menu buttons came up just as my main SL Viewer. Which is kinda cool.

Experience
The first thing I noticed is this viewer has the problem that first clicks on doors do not appear to open the door. It opens you just don’t see it open. You can see it the second time the door opens or closes.

