I like buying from Buckeye Field Supply more than BRS, but to each their own. Air water and ice is a sponsor here, there prices are great.
Most 75gpd units use the same membrane, DOW filmtech. Even my SpectraPure uses it, just rebranded (I took their sticker off).
75gpd is a bit misleading. That is with 50psi. I get 65psi, which according to SpectraPure puts out 90gpd (thus their higher than normal rating).
I concluded that each 75gpd unit is basically the same. Some just have pre-filters.