How does it work on pine or maple?

Reclaimed gray was designed to work with woods with higher tannic acid. Reclaimed gray will have little to no effect. We will be releasing a version for low tannin woods ie; Maple, Pine and Hickory within the next 6 months

How well does this work with red oak vs. white?

Most of the pictures on the site are Red Oak, the lower the grade, the more variation in the finished product. White oak tends to be a more uniform gray, but also depends on the grade. Reclaimed gray was designed primarily for Oak.

May we use European Oil finish on it (Rubio, Pallmann Magic Oil, Osmo, etc.)

We have done many floors with the Hard Wax Oil's, and it works great. (Has the same issues as with any water popped floor)

Would you say that this product performs better than other aging products

Depends on the dilution rate, but you need to dilute Reclaimed gray with 5-6 parts water to get a result similar, to other aging products