With my Technic sets, I've now started to only apply the stickers that are used for functions. Almost everything else I leave off (except for the Porsche - that stuff was necessary and relatively few in number)
Well, I disagree. The stickers make everything "come to life" so to speak. I always buy a spare set too.
As for the Porsche. Well that thing needs a damn site more than a few stickers.
I think it's fugly. Looks like it's been involved in a heavy crash and put back together again by someone who's not all that familiar with where all the bits were supposed to go.
Sorry.