A Q Switched laser is know as the best laser to treat pigment. This is used for individual spots. If there are many tiny spots, laser resurfacing with the Fraxel 1927 is a great option. Sometimes I'll use both at the same time. The lighter spots are harder to remove than the darker spots with the Q Switch because the laser has a harder time seeing the pigment. Most spots can be removed with these lasers, particularly with the 532 and 1064 Q Switched laser.
It's not possible to say for sure without seeing you, but in general brown spots respond very well to Q-switched laser treatment. In my office, if we have a patient with brown spots that don't respond to IPL, we usually treat with Q-switched alexandrite or Q-switched YAG laser. These lasers are non-invasive. Sometimes a stubborn brown spot needs to be treated more than once. I would strongly recommend that you see a dermatologist to make sure that the brown spots are properly evaluated and treated.