Technically there is no Bosch S5 battery for the Golf Mk5 platform.
I wanted an uprated battery due to my compressors and audio set up (so high drain on battery) and we tested a few out and found the Bosch S5 007 fitted a Golf Mk5 (despite being reportedly about 7cm longer than the stock battery).
It fitted fine.
It is a 750cca battery with 74ah and of course the 5 year battery. Probably little in it compared to similar Varta units. Bosch is just a nice name to have. Looks a bit nicer when you lift the bonnet and remove the battery tray.