The iPhone 3GS was the first iPhone to emphasize speed. The iPhone 4s did but not in the same way the iPhone 5 did. That phone ran iOS 6 like a champ!
The iPhone 5s ran iOS 7 pretty much like the iPhone 5 did, and the iPhone 6 did not increase speed much (if at all). But the iPhone 6s makes everything instant like the iPhone 5 did in the iOS 6 days!
Weird that this seems to happen every three years and does not discriminate between "regular" and "S" models. Perhaps it is due to the fact that these three iPhones all roughly doubled their speed compared to their predecessors while at the same time doubled the RAM?
The iPhone 5s ran iOS 7 pretty much like the iPhone 5 did, and the iPhone 6 did not increase speed much (if at all). But the iPhone 6s makes everything instant like the iPhone 5 did in the iOS 6 days!
Weird that this seems to happen every three years and does not discriminate between "regular" and "S" models. Perhaps it is due to the fact that these three iPhones all roughly doubled their speed compared to their predecessors while at the same time doubled the RAM?