I use my McCormick extracts every feeding from veg to flush.
This time around I have Strawberry Dreams using McCormick's Natural Strawberry extract. Like above said, it really brings out the floral aromas of the plant and if you use UV during flower...but be prepared if using Vanilla, Almond, Clove....shit will overpower you every time you walk in grow spot!!!
Don't use extracts for specific strains that have their own unique aroma like Diesels, you get product with a weird, dank basement/armpit stink!! Weird but been doing this since the 90s...