i have been going back to nikon agent around leng kee road to have all my nikon cameras and lens serviced. i find that the agent is normally more reliable. if a circuit board is damaged, it will be replaced with a new board. moreover new and genuine parts are used. if the parts are no more available, they will advise their customers accordingly. while you should be prepare to pay higher price
for those repair shops, i am highly suspicious of the quality of the work done as well as the parts they use. how can the prices differ so much if genuine and new parts are used. sometime it is not wise to try to repair the components on circuit boards.
so yes, usually higher price. but think about the quality of work and peace of mind.