Get the 15-1994. We've been looking at the 15-2104, but it lacks many of the useful functions of the 15-1994. The most important of which is the ability to use long macros (15 key presses) on any key. the 15-2104 limits you to using only 3 key presses on 4 buttons only. You can work around that if you have made a JP1 interface connection (
[Link: hifi-remote.com]), but for the user who wants to use it straight out of the box, it this is a seriously limiting feature
If you have no interest in using macros to control multiple functions with one button push, then the 15-2104 does have some interesting features like Genre keys where you can store 3 favorite channels for rapid access.
I have also found that the 15-2104 is much less ergonomic than the 15-1994. The 15-1994 feels great in your hand, and the button are laid out very nicely. The 15-2104 has also changed the channel and volume keys to individual buttons instead of rocker switches found on the 15-1994. The rockers are much easier to use.
To summarize, IMO i would get the 15-1994 (they are going to be REAL hard to find soon) as my everyday remote. It is cheaper and has more functionality right out of the box.
Dave