I can only find very superficial reports/blogs of users trying out one or the other. - All of which lacking entirely of technical details.
The closest thing I could find is this probably hopelessly outdated and hard to understand comparison by the MicroPython project.
I would be interested in the obvious questions:
- flash usage
- RAM usage of VM after bootup
- RAM usage in usual use
- execution model (i.e. how are the ESP8266 "tasks" mapped?)
- execution performance
- ease of extension (i.e. module addition)
- anything else that might be relevant
From studying the documentation I believe to have understood the following:
- NodeMCU has fairly fine-grained build options that allows building only required modules. This appears to allow working with small flash sizes. For Micropython 512 KB seems to be the absolute lower limit in which case no space for user-defined code remains. Not sure how this compares to NodeMCU.
- MicroPython has a built-in WebREPL that is auto-configured by default. NodeMCU seems to have nothing similar built-in.
- NodeMCU seems to benefit currently from a larger community, presumably due to it having been around longer.
- MicroPython documentation is fairy informal, lacking entirely when it comes to extending the C code. NodeMCU documentation seems to be excellent.