Differences in light brands

[old blue]

I'm getting ready to upgrade from my 400w digital to a 600w digital and wanted to know if there really is a difference between Htgs Growbright 600, the Agromax 600 and the Sunmaster 600 bulbs? Is the Sunmaster really worth the additional $34 upgrade, or r u just paying for the name? All 3 bulb specs r exactly the same. I don't want to dish out extra money if there isn't a difference.