iOS 8 on the iPhone 4S: Performance isn't the (only) problem

New OS wants screen space and processing power that the old phone doesn't have.

iOS 8 Hinders iPhone 4s Performance By A Huge Margin

iOS 8 review: the iPhone and iPad get customised, extended and deepened, Apple

iPhone 4S owners file suit against Apple, claim iOS 9 made phones unbearably slow : r/technology

iOS 8 Download: Should you update your iPhone or iPad?

question] Can someone identify what iOS this iPhone 4s is on? : r/LegacyJailbreak

iOS 8: 35 Problems and Bugs and How to Fix Them

Vodafone UK warns iPhone 4S owners not to upgrade to iOS 6.1 due to 3G bug

Read this before upgrading your iPhone 4s to iOS 8

Read this before upgrading your iPhone 4s to iOS 8

iOS 9 on the iPhone 4S: A stay of execution, nothing more

iOS 8 on the iPhone 4S: Performance isn't the (only) problem

iPhone 4S review - The Verge

Apple iPhone 4S Review