Ive had a few versions of the Bosch powerboxx ( the early adopters were guinea pigs as there were numerous basic usability fixes causing several similar versions...). Also have the Milwaukee M18 version (Rockford Fosgate sound), and now use the Makita and the little M12 Milwaukee.
The bosch sounded good, was loud and had a gfci power strip on it as well as charged the batteries. But, it was huge, the cord was short and the battery charger took forever to chargea batt. The milwaukee had the best sound, but i didnt have any of those batts. The Makita is medium sized, easy to carry, can store 2-3 extra batts i. The batt compartment and is durable. Sounds pretty good, but does have the side facing speakers.
The little M12 milwaukee is small, durable and sounds great for its size - love it for all of those reasons. I dont use any of the milwaukee m12 tools, but the battery port is near identical to the Bosch 12volt max batts except for the polarity id reveresed, so its an easy conversion to use the m12 tools with the bosch batts. You do have to open up the tool and rewire the batt connections for the polarity, but thats pretty easy to do. Also have to slice about 1/2" off the bottom of the battery compartment to allow the bosch batteries to make the connection. Amazingly enough, even after removing that 1/2" of material, the bosch batt still clicks into place with it's tabs.
Jt