If they’ve not been serviced for a while, send them away. As above, Loco seems to have a good rep, he certainly sounds knowledgable on here, anyway.
But it’s definitely worth taking the time to learn how to do the quick service yourself. Lowers off / clean / replace bath oil. Takes 10 mins once you’re confident and makes the forks feel instantly nicer, plus no doubt it keeps the forks happier for longer. My advice would be to do that pretty regularly (say, after every 20 hours of riding) but don’t mess with the damping / spring internals unless the forks develop a problem.