I can only speak from my own experience, but my two males get along great. Snickers was 11 months when we brought Baxter home (at 12 weeks). From the first, Snickers showed who was top dog and Baxter didn't know any better. He was just a baby and he was oblivious. In time, they became friends and Baxter accepted Snickers being the dominant one.
Now four years later, they are best buddies and brothers. You never see one without the other, and they always have to know where the other one is at all times. Once in awhile they'll fight over a toy, but it doesn't get out of hand.
I've heard that male/females get along better than two of the same sex, but honestly it has been a blessing with our two.
