Both myself and my wife had 'Salomon Quest' boots on for the WHW in September. We already had these boots for a while but considered getting trail shoes for the trip. We carried all our kit with my rucksack at about 9kg in total and wifes at around 5kg.
After about day 3 my feet were killing me. The soles of my feet were aching after 2-3 hrs of walking in the morning from that day onward.
Have worn the same but several times since and been up may munro's for overnight wildcamps and not had the same issue. The paths and old military road type heavy gravel seem to take there toll on my feet anyway.
Still not sure if cross / trail trainers would have been better or worse. Maybe just have to do the WHW again to see.