I'm trying to decide between these two mowers and maybe the SilverPro series of LB. Other than a larger gas tank, metal wheels and an engine cover on the Commercial unit...what's different from it and the GoldPro? They both have the same engine and aluminum deck but the GP is quite a bit le$$.... Anything? Thanks, John btw-this mower is for my 1/2 acre yard and not for commercial use...I just like to get the best I can afford (which is around $400ish).