For larger stores which have a basic always-on internet connection it will be much faster. In my experience 2-5 seconds is what you see for mobile devices that

For larger stores which have a basic always-on internet connection it will be much faster. In my experience 2-5 seconds is what you see for mobile devices that use 2G or 3G, or places that still use some form of dial-up for every transaction (ISDN still exists..).