This isn't my answer, but use the search and read up on S-04 in the forum. There are lot of threads about it and you might get more info that this single thread.
With that said, I'm in the S-04 camp. I like that yeast. I use it mostly for English styles, but I have used it in other beers too and it does well even in a Pale Ale. I find it's flavor clean, but not neutral if that makes sense. It has a bready note to it and sometimes just a slight tartness. I like it in English Bitters. I have use it in a Porters with good results too. If you use it, I like to mash higher because it likes to clear well but it's also more attentuative than most English yeasts.
It's one of those things you won't really know until you try it out. It's not a first pick for an all around yeast, but keep it for an English Bitter, a Porter...in a Brown Ale or Stout I can't say I have used it for. I like to keep it around 66*. It seems quite balanced at that temp. It can go lower but think that might accentuate the bready character, you go higher towards 70* or so and it can get a tart/tangy/fruitier character.