personally, I think a touchscreen is an absolute necessity for a carPC (for GPS, playlist management, etc), but I don't like using it for everything. I hate controlling volume and equalization via software/touchscreen; for those basic functions I need knobs!
in my first carPC system I kept a head unit, so I kept full hardware based audio control. then I overhauled my entire setup and went "headunit-less". I ran it like that for a couple weeks but I hated it for several reasons: 1.) I had to look at the screen to simply increase/decrease the volume; 2.) I had to go through multiple screens to change EQ settings, which required taking my eyes off the road longer than I was comfortable with; 3.) with RoadRunner [w/DFX3.0], if you try to play a song that winamp doesn't like, winamp becomes the primary window but RR stays on-top, which results in RR locking up (it won't recognize any touchscreen presses, you can't close it, adjust volume, or anything).
for those reasons I knew I had to have at least a hardware-based volume control, if not full hardware EQ control as well. I know many members use physical volume knobs (like the griffin or space navigator), but they connect via USB which means they are still software controlled. this was not an option for me, I needed a real volume control, not software-based...
in my newer setup, I didn't have room for a HU in the dash so I bought a half-DIN graphic equalizer and mounted it below the touchscreen/monitor. this gave me the best of both (or all?) worlds... It gave me full volume, fader, subwoofer, and EQ control with physical knobs that use without the need to look at the screen. and if the computer froze/locked-up, I can still control the volume. I love the 7-band equalizer too because I am never happy with a single EQ setting, each song/style requires a different EQ setting to sound good and now I can adjust it by simply turning a knob (I don't have to go through several menus/screens to get to the software EQ screen. I still use the touchscreen to manually change tracks, playlists, GPS destinations, etc, but my most used fuctions (volume, sub, and EQ settings) are all controlled with physical knobs.
here is my current setup:
I would recommend you not choose between a touchscreen OR knobs/buttons, but use both. there is no reason why you have to choose between them when they can work in harmony. good luck with your future carPC setup
