MIUI 7 will roll out for Redmi 1S, Redmi 2, Mi 4i, Mi 3, Mi 4, Redmi Note 3G, Redmi Note 4G. According to the MIUI Forum The Mi Note Rom is still in beta version. So Xiaomi will release it officially when the Rom will be more stable. BEta users can test the MIUI7 Rom for Mi Note.
MIUI 7 is a big change from MIUI 6 specially in performance, battery life. The UI is redesigned and added so many new features and themes to make it look far more better than MIUI 6. Now you can block notifications for special apps in the notification shade. The icons too have been redesigned.