Ranked in these QuestionsQuestion Ranking
Pro Fully open source
More trust worthy than the official.
Pro Matching UI
No differences between the official and FOSS UI and settings.
Pro Dont need Google Play Service
Telegram FOSS have Notification Services, they can running in the background without GPlay Services or another services.
Con Slower updates
Con Emoji is ugly
Using FOSS emoji but this one is not good as IOS emoji -_-