Here are a few elements of this movie that might appeal to some people:
Firstly, it presents a clearer, more sensible idea of how virtual reality works than its 1999 movie siblings "THE MATRIX" or "eXistenZ". And it does it thoughtfully, without mind-numbing action scenes and special-effects.
Secondly, the virtual reality world of L.A. in the 1930s is visually rich, yet doesn't stray too far from a realistic look.
Bonus extras are Armin Mueller-Stahl's, Vincent D'Onofrio's and Dennis Haysbert's performances, Gretchen Mol's lusciousness (also enjoyably down-to-earth as a grocery clerk), and exquisite direction and photography (Josef Rusnak, Wedigo von Schultzendorff)
On the DVD, director Rusnak makes the accompanying commentary in the way I like -- he comments on what we're watching with relevent and interesting behind-the-scenes info.
I rewatch this film (and film with commentary) frequently for these reasons.