Talk to the builder about both and why they picked Blue Plus. Advantage/Disadvantage of both. Advantech is excellent. They might be making more profit on the Blue Plus which wouldn't surprise me in the least. Do your own research.

Advantech is really the gold standard and I wouldn't use anything else.

Both products are made by Huber and should perform well. The Blue Plus currently retails for about $10/sheet less than Advantech. For homes with a large footprint the cost savings can be appreciable.