So my father in law built our master bedroom/bath and installed the lowest rated, low gpm shower valve and head combo. Originally I thought it was my galvanized pipe with years of corrosion. All replaced and back on, yay! I am beat😩. So after researching my shower valve and head, it doesn't have good reviews, only 1.8 gpm. I want a shower to peel paint!! Not really, but you know what I mean. I have this Glacier Bay combo kit and was looking at this Moen unit with 2.5 gpm. Should I notice a substantial change?