Going back to your original question: I purchased the
MX-350 as a replacement for a RF-20. The main reasons:

1. The backlighting on the RF-20 is terrible. It's red,
it's uneven, and it's dim even with brand new batteries.
The light (such as it is) shines through just the text
that is etched into the buttons. There simply is not
enough light coming through to make the text legible in
the dark. To me this essentially defeats the purpose
of backlighting. On the MX-350, the buttons are completely
illuminated, and the text stays dark. As such, the text
is actually back-lit, making it far more legible in the
dark.

2. The 4-way controller on the RF-20 has a mushy, cheap
feel to it, with much less tactile feedback than the same
control on the MX-350. Also, it's shape is completely
different. On the RF-20, it is kind of scalloped (for
lack of a better word) and it forms a sharp edge that
is uncomfortable on the thumb after a few successive uses.
It's made of hard plastic unlike the rest of the RF-20's
buttons which are the soft rubber, and this only makes
it worse. The same control on the MX-350 is far more
comfortable to use, and it make the entire remote feel
like a much higher-quality unit.

3. We prefer the gemstone buttons to the soft rubber
ones.

4. We like that you can have separate macros for each
device on the Power On and Power Off buttons.

Also, we will probably never take advantage of it, but
the MX-350's code database can be updated and it's programing
& configuration can be archived and later reloaded using
the PCL-300 ([Link: universalremote.com])

For us, it was no contest. The MX-350 is well worth the
price difference.