Any negatives for Grow Bright bulbs?

[ProductiveSmoker]

Need new HPS and MH conversion bulbs. HTGsupply.com has the Sunmasters and Agro Suns around $65-85 each and the Grow Bright brand is only between $30-50 each. The lumens are the same if not better than the Sunmasters but is there anything else to consider? Any noticeable decreases in growth rates with the Grow Bright brand?

Thanks!