I would not - the BL2 goes lower and is more powerful. If you like its effect, keep it. The BL11 is possibly going to be better for music but less impressive for LFE in movies. However proof of the pudding will be in the eating!
I can see one role of the BL11 as being used with the BV10 when the BV10 is a stand alone set. It will add the bass that the BV10 lacks.