Just finished my 1st Panelview Component....also a C400.
Have done many Panelview Plus apps.
One major beef with the C400.
Whoever thought that numeric entry keypad was good enough must have been drunk. Unless you have fingers the size of pencil erasers it's a PIA.
When you have a small touchscreen you better either use the whole screen for numeric entry or at least give the developer a way to customize it.
Until that is fixed I will not be using another one.
I have 1 PVc600 that has a date of Oct 2012 and its numeric keypad was very small. However we just received a new PVc600 with a date of Oct 2013, and thankfully it seems that the numeric keypad has gotten significantly larger. Its a little more responsive too.