Mike: 100kHz steps is pretty coarse resolution, some bands might only have 1 to 3 points with lots of wasted points between ham bands; you might want to take narrower sweeps of the bands you plan to use and store several calibrations so as not to spread the measurement points so thin. Or just bring the calibration standards along and calibrate on the fly; a 1-port reflection calibration is only 3 measurements.
Instead of buttons see how you like using the touch screen, it works well with a stylus (a mechanical pencil works well and can be used for notes and logging) and I find it faster.
73, Don N2VGU
Donald S Brant Jr