It's been just over a year I've got my Merida. It's done 9000 km (according to Strava). I rode the bike in every condition, often in hard terrain (well, hard for me! LOL ).
It's got Manitou Marvel Comp forks. They work flawlessly, very smooth, no play, no strange noise, no damaged seals, no leaks... The stanchions are like new really. After every ride I clean them from mud/dust and treat them with Brunox forks Deo thing.
Should I consider servicing the forks, even when they work perfectly? I'm afraid it could open Pandora's box... 8)
im one for if it aint broke dont fix it
Definitely service them. However you think they feel now, they'll feel better after a service, with fresh fluids in.
The exterior of the fork may well be fine, but any contamination that's made its way past the seals will be eating away at your bushings and stanchions The damper oil may well have emulsified, especially if you ride somewhere pretty rough.
Put it another way - would you avoid changing the oil in your car, just because you wash it once a week?
Forks aren't rocket science. Take your time, read the manual - it's only an hour or 2 for the first time, and a lot less once you get your head round what to do.
At least perform a lower leg service if not a full service. As JonEdwards says you don't know what's going on internally.
Lower leg service is often very simple and worth doing. Don't know about those forks, but Rockshox forks are always easy.
Uppers on mine are relatively easy too.
I didn't service my old Recons for 4 years. Not sure they were any different after I had. Have replaced with Pikes and they're night and day difference. They'll get a lot more attention as they need to stay feeling nice. The Recons were just cheap old forks that bounced and not much else.
My Lyriks on the big bike gets more love as they need to stay plush. I left them a bit initially, about 2 years, and did a full service. They did feel more plush after that.
p.s. Check for bushing play by trying to pull the stanchions sideways while holding the lowers (don't hold the bridge!). If no play then bushings are good. Replacing/fixing bushings however is not a simple/cheap job. They generally last ages though.
If you have the funds then service them annually, you wouldn't wait for your car to start making strange noises before you serviced it would you?!
Prevention is better than cure.