Review on M5Stack Core2 ESP32 Development Kit 2nd Gen Core Device CP2104 MPU 6886 BT WiFi Dual Core 32-bit 240Mhz LX6 CPUs 16M Flash 8M PSRAM for UIFlow MicroPython Arduino by Daniel Fung

Very good platform and mostly open source. Please note this is NOT the latest version of this kit. From January 2018 there is a new one with 4MB PSRAM. There are several quality issues due to loose connector pins on both the inner and outer connector below. They're a bit loose and have intermittent contact, causing random reboots and connection issues. They can be repaired by GENTLY pulling the plastic case up off the pins, bending the pins together slightly, and then replacing the plastic case. It hurts, but it only takes a few minutes and fixes the problem. There are also some issues with flashing the new firmware that can be fixed by soldering a 2.2uF capacitor between the RST and GND pins. This can be used with Micropython and the online IDE is good.