I used a mixture of vinegar and vodka in my 30. I started out with just vinegar, then added the vodka later on to round out the potion. Works really well, but you have to start super slow, and you can't let your alk get above 8. Anytime my alk went past 8, you could instantly tell. Most SPS were p-o'd, and I would get the classic "burnt tips". My birdsnest were very sensitive to the changes in alk while carbon dosing as well.
I think it works wonderfully. It works better for nitrate reduction than phos. It will allow you to keep a heavier fish load as well. I had 12 fish in my 30 and my SPS looked awesome. Nitrates were below 5 and I would keep phos below 0.05 with a little GFO (2-3Tbsp).
There's a great write-up on the vodka dosing. Vineger is just 8 times weaker. Vinegar is gentler and less room for error and there is less associated cyano. I was also adding a drop or 2 of MB7, something I picked up from Nick (Blueline).
My current tank is set up for carbon dosing, but I'm not doing it because its not needed at the moment. I do have a third doser and container already set up for it in case I decide I need it.