Hi Ronin1973,
I do not have a modular setup yet, but as a guitarist using my guitar pedalboard at hand level for years, I feel I can answer you at least partially:
Depends on what you intend to do.
In my case, I liked to sample my guitar either with a looper at my feet or with a sampling pedal at my hands, which I would activate with my picking hand after the picking action (I use no plectrum, which probably helps). After that, I would manipulate the samples/loops with my hands.
If you intend guitar playing in the most common sense, then a foot-controlled setup is definitely better, but if you are into sample and hold manipulation, hands level controls are great.
In addition to this, my idea was using the guitar signal's envelope/gate along with a couple of expression pedals to control some things hands free.
I would be interested to see how anyone actually did that too in a live situation.