To add to grego's post, I too was unsure about spacers/adapters. I would always hear negatives about them but I didn't like the way the stocksetup was tucked in there so I took the leap.
I am happy to say that after 4 years of running the spacers/adapters I have yet to have a problem with them. Like some people I do alot of hmmm... High Speed Driving
I have also done some light off-roading and still not a problem (knock on wood)
I'm not saying that they are extremely reliable cause I have only had them for 4 years but all I know is that after these past 4 years the units do not have a single blemish. Just my 2c.