The permanent outdoor lights really are a great solution for Christmas lights. Definitely recommend using the support brackets along with the adhesive strips though. The adhesive only lasts so long.
I would reccomend using the supplied brackets if your soffits aren't perfectly flat and use rubbing alcohol to clean the surface before you stick the 3M tape. A lot of reviews complain about the tape not sticking but if you clean the mating surface properly, it will stick just fine. Again, the brackets give extra security to make sure the lights stay in place. The lights look great and I love the fact that I won't have to hang lights now every year.