I've been using several of the Sonoffs. (Primary the TH16, Pow and Pro CH4.) The builtin fw (before the IFTTT update) was fairly useless, so I reflash all devices. Which is fortunate, as the combo with simple Arduino OTA + Blynk is absolutely fantastic.
However, I've come to a point where the Sonoffs become too limited and troublesome: There're no IO terminals! Most of the devices has some hidden IOs, that can be accessed with soldering. (Which is annoying!) The Sonoffs TH has 1 IO, that can be accessed through a 4 pin jack. That's much better than no exposed IO, but the mini jack plug is still annoying to work with and it's not suitable for long term installations.
The Sonoff Pro 4CH will have to compete with devices as the Industruino. Unlike Sonoff they all have plenty of IO terminals. The price is not that different from a Pro 4CH. Unfortunately they have no builtin WiFi. (Only hacks.) But that might only be a matter of time?
So, more exposed IOs, accessible through exposed terminals!
This feature request is the same (more or less) as the following: