The SKS fenders seem to be a much higher quality material than the Bontrager NCS fenders. SKS feels like it has flex and can bend without cracking while the Bontrager feel more rigid/fragile.
I did use my drill and I slotted the hole to the side a bit so I could line it up with the tire. I did have to use a very short headed bolt to clear the tire inside the fender as well - used the one that came with the NCS fenders as the bolts that came with the SKS were too thick to not rub the tire.
All in all it took me about 2 hours to install the fenders/adjust them/etc but I'm very happy with them compared to the Bontrager NCS. They also look much cleaner because they don't have that 'NCS' adjustment where you have the two plastic pieces in the middle and the double strut for a short span - the struts for the SKS almost disappear against the spokes of the wheel.
I'll post up a picture later - they're on my phone and it's downstairs charging
That said - is there a section here on bikeforums where I can put the Bontrager NCS up for sale? Probably just $20 + ship - they're definitely still usable I just didn't really like them.