Hello,
I would like also to share my experience with shelly button and to compare with myStrom button.
In general I am very happy with all the shelly products I have installed in my premises.
Now comparing the shelly button with mystrom button:
Shelly is easier to integrate as it supports connecting to specific mqtt server. Configuration is also much easier with the web interface.
Mystrom does not support custom mqtt connection but http requests. Configuration is performed with http requests also which is much more complicated.
However, mystrom is super fast in executing a command from deep sleep.
It completes the request in ~1-2 sec.
Shelly in my cause takes 7 seconds to connect to my wifi network.
Then in ~1 sec it completes the rest steps (DHCP ip, mqtt connect + post).
I am using a mikrotik, high performance, router which is very fast in accepting clients and assigning IPs. Shelly is using the latest firmware.
I am sure mystrom has optimized the association to an AP somehow.
Please try to improve this part in shelly button and the product will be really amazing.
Thanks.