I had my MacBook Pro calibrated by a friend with their Spyder 3, ordered prints from professional printer (NC Tricolor) and the prints returned darker than the prints on screen. So I went back to my friend and we re-calibrated the screen, and he used his "professional printer" to print the photos. I still didn't feel they matched (my friend thought they did - friend is long time photographer and used to calibrates his monitor regularly).
I decided to take advantage of the great sale Amazon had on the Spyder 5 Pro recently and just calibrated my monitor (using Damien's instructions and in a completely dark room). Wow what a difference! Only problem now is the photos on the monitor look amazing, and the prints are way dark. I have checked the lighting in the room, it is white light vs yellow, and a pretty bright room. Do I need to resend the photos to be printed? I have NOT re-calibrated using the white balance suggestions in the troubleshooting instructions. Mostly because the photos on the screen look so awesome (wrong answer I'm sure since the goal is to have the screen match the prints)