Can anyone explain to me what the "cinema mode" on the old DX110 actually does in terms of screen and pixel aspect ratio? It certainly doesn't do the same thing as my Sony VX2000's 16:9 mode.

The VX2000 has an anamorphic 16:9 mode (albeit low resolution) and I'm guessing that your DX110 only has a 4:3 letterbox cinema mode. What is a DX110 similar to in NTSC countries? It looks kinda like a MX3000.

Both lose 25% resolution but the anamorphic squeeze of the VX2000 might looked "squeezed" on a 4:3 TV.

This link (http://www.maxent.org/video/16x9.html) goes over the various ways that native 4:3 camcorders record 16:9.