If it is truly refurbished by Nikon then yes i would trust it. Jake2k just picked up a nice 18-105 refurb and it works like it was new. Basically Nikon takes a product that may be malfunctioning in someway and they will bring it back up to the standards Nikon would have for any new equipment, but they can't sell it as new since, well, its not. So i would say yes, and if it does malfunction on you you can send it back to Nikon i believe all of their refurbs are guaranteed for 90 days. If there is a problem with the lens it would most likely happen within those 90 days so i would say go for it.

Also Jake2k just sold that same lens for a bit cheaper to pay for his new one. I like the 18-105 much better but to each their own.