it always on product page
(personal opinion) - the main driver for upgrade not only new feature, even 5.5 cover 90% of users needs
the main reasons is compatibility
few years ago Mac stop support Java 1.6, but Talend 5.x do not support 1.7(1.8) - reason for migration
2 years (=-) Amazon change used java library and Talend 6.1 stop work with S3 buckets, was resolved by loading user libs, but again reason for migration
life is not stop, and in multi vendors word - it would happens permanent, a lot of people like XP ... but manufacturer no more support it on new PC ...