Not much, just some little things. Like it'll take longer to chill, and maybe longer to come to a boil depending on how you sparge. Otherwise, I almost make 10 gallon batches now as a 5 gallon batch is just as much work as 10 gallons!
My husband used to try to stop me from making 10 gallon batches, as it seemed excessive. But he's now the biggest proponent for the bigger batches. Twice as much beer for the same amount of time and effort. If you have the mash tun, boil kettle, burner, etc that can handle it, it's so worth it!