LAST Record Preservative. Do you believe?

I am starting with this stuff on my cleanest most loved lps. How many people use it? Have you noticed longer preservation? I have read alot possible alterations in sound, but I think they must be quite subtle, if at all present.

Also, do you fill the syringe and apply to the applicator for each side, or just once for both sides?

Do you use the STYLAST, and if so, do you apply it before each side of an lp?