You asked what the advantage is. I told you what they are for me;
co-located equipment, easy installation and a clean dash. I use three hoses and 6 points of potential leaks. The mechanical set-up in the photo I provided has 18 points for potential leaks. (Where the hose connects to a joint of some sort)
I won't need to worry about the long hoses from the cab to the rear air bags rubbing, wearing or something snagging them under my truck either.
I forgot to mention the wireless system constantly monitors the air setting and adds or removes air as needed to maintain the set pressure to within 3lbs.
There is also 3 presets you can use depending on your loads.
There is a warning program to alert you if there is a leak in the system.
Besides, it was cheaper for me to go wireless. Cost me under $250 total with the rebate and purchasing from Amazon.