The G500s also comes with double the RAM of the G505 - 8GB, that is - which should be plenty to keep it ahead of the game. Bear in mind, this is still meant to be an entry-level laptop, and so its main tasks are to be checking emails, surfing the net and working in various desktop applications, but with the added power that the G500s could be future proof for a good couple of years before the ravages of time take hold.
The G500s is a touch more expensive than the G505, at £400, but is it really worth the extra outlay? Or, are you simply paying the extra for the superior badge?