I've had graphtech saddles on my guitars for years, so some of my original impressions are long gone! However I do remember that they don't suit all guitars. On my walnut custom with Wilkinson VS100 bridge, they made it too bright (pickups are MQ, Slowhand & Mini-Mule).
I didn't change because of the adjustment screws (I have fitted the right length screws [there are 3 lengths available if you check on line, but only 2 or 3 are put in the saddles as standard]). I changed for the sound, it is more 'glassy', especially if you go with a Tusq nut. I had brass saddles in the 80's (that's where gwEm's came from!). I liked the sound of the guitar then, but it had EMG SA's on it, so it wouldn't sound the same today!