yes, absolutely!!!
How heavy do your dumbells go? I only ask because with the PLB it is possible to go heavier than you are used to, say on MIS, because you are doing fewer reps at the heigher weights and you can really challenge yourself. So, if your dumbells don't go that high, you may end up buying a barbell eventually. I just had to do exactly that, and I have to say, that I now prefer using the barbell for lower body work, I am able to balance much more easily, and I can go much heavier.
Clare