I think the standard labelling for power consumption on ampilfiers is what they consume when operating at a set percentage of output that's supposed to represent normal use. For example, the back of my GK MB200 says "Full power 240w, average power 48.6W" next to the power socket. I'd presume that your Roland quotes the lower figure.
Still even considering that, the Behringer's consumption seems small for it's advertised output.
Quote power consumption at 1/8 power. This is because speech and music are not continuous and 12.5% is considered the normal power draw. Instrument amplification should be rated much higher, especially bass as the power drawn for lower frequencies is higher.