I have heard of Bosco levers, but never used one. Levers are simple in design/function/maintenance, but don't mistake that simplicity for being easy. You have several types of levers... a true manual is where YOU control the pressure based on leverage. Then you have spring loaded, where you preload the spring, release and the spring controls the pressure/flow rate. Also, there are some that also incorporate pumps to go along with the lever action. Guess that would be considered a hybrid of some sort.
For years I owned an Olympia Cremina, which is a small, but awesome home manual lever. Even though it's a superbly designed/built machine I can honestly say using a manual lever day in/out will take a toll on your joints. On a commercial level I imagine it would be insane over time doing so. I no longer have that lever, but do miss using it... my rotator cuffs don't miss it though as some days it was unbearable to crank out just 3-4 doubles.
In a high volume setting you may want to look more toward the Linea or similar. I worked on a 3 group Linea for some time and it was just OK. Main thing I didn't like is the lame steam valves that take a lot of time to use for something as simple as steaming. Commercially I owned a 2 group NS Aurelia and that thing was much better than the Linea I had used before it. The Aurelia has fantastic thermal stability/consistency and the steam valves are lever in function and drastically better than the standard twist type valves. Much quicker and more control...