None of the existing display configuration tools does what I think is "the right thing".

• Don't start from a stored config, use xrandr to read the systems' current state
• Allow creating "profiles" that will get applied smartly (not there yet)
• Generate a xrandr invocation to reflect the desired configuration
• Allow per-monitor scaling
• Allow arbitrary monitor positioning
• Implement "scale everything so all the pixels are the same size"