--As a note for others who might want to know--
The low iron Mr.Aqua appears to be a bit lower in quality to the truaqua brand low iron tanks (which are close to ADA quality imo) in clarity and seam work. However, it still looks nice and you won't find another tank this dimensions unless you custom build it yourself. I can see the small difference in person between those two tanks. It might be because the Mr.Aquas glass is also much thicker then ada or truaqua low iron tanks. This may account for the lower clarity.
If you have the little extra $$ when buying a Mr. Aqua 12g long I would say get the low iron, if you don't you won't miss out too terribly.