I'm somewhere in between on this. I don't like overly cluttered builds. More recently, I have been incorporating more clutter in my houses but I want to add that for my sims.
I prefer functional items over non-functional ones but I incorporate a small amount of clutter into most houses.
I avoid most gallery downloads now because of the lack of playtesting and excessive clutter. If I'm downloading, I'd rather almost have a shell to fill in. Replacing clutter and personalizing is something I do when I add a downloaded lot which is less often now.