Just an experience to share:
I brewed a dry stout a while back. It was a very simple recipe; the classic dry stout according to Jamil. 70% base malt, 20% flaked barley, 10% roasted barley. It underattenuated for reasons unknown, but not badly. I kegged it and carbonated for the stout faucet using my method that I thought I had worked out, which was to hook it up to CO2 for a few days to overcarb it, then vent it repeatedly until it didn't offgas any more. Basically carbonated at 0psi for 40 F, which is 1.3-1.4 volumes. I served a pint through the stout faucet and got no bubbly cascade, no head, and a very very bland taste. I knew I needed to troubleshoot something about it but I didn't have time for quite a while, and it was drinkable, so I drank it now and then but really I stopped enjoying it and, with a move coming in a few weeks, I was debating whether it would be worth the trouble to transport a partial keg of bland stout. I realized something though: if the beer is being pushed through the stout faucet and not coming out foamy, it must be because there is no CO2 in the beer. I hooked the beer up to CO2 for about 5 days, then put it back on nitrogen and poured a pint. It came out a milky tan, cascaded to a nice creamy head, and I figured that was cool, I fixed my no foam issue, but I was really surprised when I took a sip. The beer has so much more flavor now, the roast/chocolate/coffee flavors are much more prominent with a little CO2 bite. The moral of the story is that if you haven't experimented with different levels of carbonation, you don't really know what your beer is capable of yet.