Not trying to discount the effect of keycap profile here, but I've experienced a similar phenomenon when trying to replace the stock keycaps on my QFR blue board with other OEM profile caps. For me at least, the mass, density and weight distribution of each set of keycaps has a profound effect on the typing experience with tactile/clicky switches like blues (and perhaps your greens). I too, love the typing experience with the stock QFR caps (the feedback/sound just feels 'right'), and just can't seem to replicate it w/ another set. For now, I'm forced to keep the stock caps on all but modifier keys, as I'm using this board 8+ hours a day and I value function much higher than aesthetics. I hope to eventually find some caps that replicate the stock QFR typing experience without being ugly as sin....