Last night I hooked up some temperature sensors, then figured out how to edit the LSX skin to change the time & date display to the output of these sensors. This took a grand total of ten minutes.
Last week I put in a RadioShark, along with a phidgets relay board to control the power antenna. I set these up so that when I go into the RadioShark plugin, my antenna goes up, and when I exit, it goes down. This all took 2.5 hours, and this was the first time I ever edited a skin.
From the community that pumps out plugins and skins non-stop (not to speak of our bionic coding-slave, guino) to the functionality and versatility of the application itself, Road Runner is hands-down the best carputer solution.
Frodoplayer is a good "out-of-box" solution for novices and for those times right after you installed your system and just want it to work now. RR really does require some effort to taylor it to your own needs.