I gave up after realizing that Signal will not deliver message for a couple of days and that message notification doesn't work. Why wasting personal credit on something that is clearly inferior from the usability point of view.
And after it started insisting on creating a PIN each time I start Signal, I finally deleted it from my phone.
You can forget about security if you can't get a seamless user experience.
Oh God, the PIN creation is so annoying. Whatever possessed them that that was a good idea? Note that even after creating the PIN the app doesn't quit nagging you, it 'helpfully' continues to remind you to re-type it so you don't forget.
Plus, it's just a terrible UX for a SMS client. I really wanted to like it, but it's just too obnoxious to use. I've certainly not recommended it, I've had better luck switching relatives to Linux mint (seriously, I am not exaggerating). Creating a group MMS is annoying, and there's a nag screen if you try to call someone from a message within the app. I understand that most of these problems are due to the secure nature of the app, but trying to use it as your full-time SMS client is just too much of a pain. I'll likely still keep it installed, as the 1 thing it does do is make it really easy to transfer files/send messages between devices (send messages to yourself, then download them using the client's for other OS's).
Since it's open-source and on GitHub, you can go there and raise an issue with this feedback. You can't do that with WhatsApp or other closed-source alternatives.
Personally, I don't feel the UX is "terrible", I can use it to do most of the things that I could do in WhatsApp. My friends and I also tested out the video call feature and found the quality to be the same, if not better.
It has happened as recently as last month with a relative of mine. On that phone, the messages would get delivered only when Signal was manually opened; if Signal was not the foreground application, messages for it would not get delivered (but WhatsApp delivered messages correctly on the same phone). It's as if the Signal server had lost the association between the Signal account and the GCM token used to deliver the notifications.
I think it used to be the case back in 2015 or so, I believe they meanwhile fixed the issue. For sure it hasn't happened to me for a couple of years now.
Ive done that too. But I've experienced a lot of people removing it again.
The result is uncomfortable, since Signal never knows the other side removed it, so messages land in thin air. Several times did I have awkward moments when someone was angry "I thought you'd let me know if it was cancelled" - "I did - I sent you a text about that two days ago! On Signal!"
To switch, or to use it? Many people I know contact me through Signal, but their primary means of communication still definitely is WhatsApp, and they'll have to consciously remember to open their install of Signal to contact me.
And after it started insisting on creating a PIN each time I start Signal, I finally deleted it from my phone.
You can forget about security if you can't get a seamless user experience.