The little I know and the information I have would suggest that there would indeed be a difference between the two products; my guess is that it would probably involve higher levels of ultrafiltration. Nerl themselves appear not to apply the "ultrapure" name to their reagent grade water.
That being said, I would expect the reagent grade to be very good and your point as to whether one could "hear" the difference between the reagent grade and the "Safe and Sure Ultra Pure" is well taken.
That being said, I would expect the reagent grade to be very good and your point as to whether one could "hear" the difference between the reagent grade and the "Safe and Sure Ultra Pure" is well taken.