It depends on what kind of beer you would like to brew. S-04 works well in both English style beers and also IPAs. I've used a few times with good results.
Some of the beers I made with S-04 had a slight tart flavour ( it works on specific styles better than others ), which is said to be from the yeast, as it produces a bit of Lactic acid. But overall, S-04 is easily one of the better dry yeast out there. It is also used commercially by many around the world. Make sure to ferment on the cool side. It tolerates high fermentation temps. well, but I think it is there where it produces the " tartish " flavour.