That extra 1/2 inch makes a big difference from 300 to 600 gallons if not more. Plus you dont even have a backup if the line gets clogged. The mag 7 pump will over drive that 1 inch. If at the vary least if you dont want to spend the extra $34 then spend $8 and get a 2nd 1 inch bulk head.
In my 58gal i have two 1 1/2 bulk heads, and not for the extra flow. Its only because if one of my drains gets clogged i know the other will handle the extra water and my tank wont flood and i wont burn my pump up. $34 is a lot cheaper than $150 for a new pump and the women *****ing me out for destroying the carpet not to mention if i kill anything in the tank.
Just my .02