With the lighter set-up a smaller prop I have found to be more stable in FFF and windy gusts but the 8" props were way too small for my 3S set-up. You want to try and achieve hover at "mid-stick" throttle while in Manual mode.
Motor Kv has to do with set-up as well, Higher Kv motors or higher voltage packs will product more power allowing you to spin that smaller prop.
My best blend so far has been 9" Graupners on my 3S set-up but hover was just a tad above mid-stick