depends on your house, really
in general, we fish walls, and you won't see the cables
but if you've got an older place where we don't have access to the ceiling in the basement (tile/drop ceiling) there may not be a simple/nice solution to get wires to where they need to be
we're able to use existing coax as well, so as long as it's in good shape, and there are no buried splitters somewhere, we may not even have to install new cable.
obviously, the quality of the job is going to vary from installer to installer, but I'd like to think that in general we all do a pretty good job