The BroTek is left in place, though there is a trap door to cover the mid pto that requires a 1/2" wrench. Taking it off requires taking out 2 self tapped screws up top and 2 heavy bolts from the drawbar area.
The BXpanded guard fits on the mower lift arms, so obviously has to come off. But it also only uses the lift pins that hold your mower up, so it comes off in about 15 seconds, if you walk slowly around the tractor.
Both great products. For me, it was BroTek because my tractor is an older model that BXpanded didn't support.