Mine took 3 weeks to mellow out, and got better with time. Mine was an OG 1.050 smoked porter. Been bottled 3 months now and is amazing!
I just did a brown ale also, and I opened the first one at 2 weeks to try it and it wasn't ready yet. 3 weeks it was much better, 4 weeks tomorrow going to try it again and should be nice and smooth!
I know people like to try stuff quick, myself included, but time really does make things better. Now that I have a pipeline going, I'm in no rush! That first brew though I wanted NOW!