I have considered using a dosing pump as well, considered a Bubble Magus. How reliable are dosing pumps? I have always had a hard time trusting such equipment. My fear is that a pump would get stuck on and overdose the system...
I've heard a lot of good things about the BM and liter meter. I talked to one reefer with a hevily stocked 250 or 300 gallon, and he said the BM could not keep up with his demand and supposedly he burned up 2 of the pumps in the first 6 mos. But this is one of the only negatives I've heard, and imagine they work great on less demanding systems