I moved to SALT (79 CHF Month including extra SIM card) from Swisscom a few weeks ago.
What made it a really good deal is that with the unlimited 4G data plan, I could cancel the home internet connection (saving an additional 49 CHF per month) and instead buy an extra SIM card (10 CHF month) and the wifi router (Huawei E5180 - 120CHF one time)
I have been running Swisscom and Salt in parallel to test the speed, and so far have experienced that SALT is so much faster (14 Mbps compared to 6 Mbps)
If you are thinking about doing the same, you need to first check your home coverage: https://www.salt.ch/en/coverage/
In addition, it is worth noting that Swisscom have a normal 2 month cancellation policy, and Salt only provides a 6 week free return policy. So it is important to agree with them to test it before they made the switch.