To be fair, every services has it's pros and cons, and for crypto, it's really a dangerous world for us because even if the project assures that it's all secure and that it can't be hacked, sooner or later hackers are going to find loopholes or any kind of attacks that can give them advantage specially in Telegram.
So for me I will be cautious, even prior, Telegram has history of hacks or at least user accounts been breached. And most likely, we will hear some kind security concerns and hopefully it will not be that bad that everyone's account will be affected with the @web wallet interface.
It is best to avoid using the Telegram wallet for your Bitcoins but above all I don't understand why I should be interested in doing so when there are dozens of safer possibilities out there. We are talking about your savings and I would never give anyone the management of mine considering that Bitcoin has really given us the possibility to manage them in total freedom