You will find all the info you need here: http://www.pbnation.com/showthread.php?t=3490753
I just picked up an NT11 after shooting Egos for the past six years and this has helped me with every question I have had. If you follow the manual you will be set.
Settings: for my NT10 I upped the dwell to 7ms but people have good results typically at stock 6 up to 9 to 10ms. Other then that I drilled out one of my spacers to 0.33in to match the black rubber diameter and mimic the green spacer (0.34in) from the NT11s. Reason I didn't go to 0.34 was then the rubber tip is the limiting factor and I didn't want that.
Spacers: Used to tune the marker to your likings. Add spacers to increase efficiency and upping the sound signature. Most people run no spacers.
Tips: Again to tune the marker to your liking. Just run the stock blue unless you start adding spacers then you might want to move to the red (smaller diameter hole).
It's an excellent marker, I'm only mad I didn't get one earlier then I did.
~ owner & driver of cars ~