Just got my Eclipse 3d2 up and working everything seems to work great except for the hotend. I went ahead and got the new E3D upgrade kit (mostly for the silicone sock) and I don't seem to be able to get the thermistor to read the correct temp. Testing at 100C with a Fluke temp probe it's reading about 93C, at 200C the Fluke is getting 181C. Current firmware settings are:
temperature_control.hotend.thermistor Semitec temperature_control.hotend.beta 4066 (have also tried several others found on the forum)
Comment out the .beta configuration line. You should use .thermistor OR .beta, but as far as I know, not both. The "Semitec" setting should be correct, even for the new E3D cartridge thermistors that are in the silicone sock upgrade kits.
I had the .beta config line blocked before and tried it active hoping for a better result, deactivated it again with no change. Turns out you still can't fix stupid, just wasn't making good contact with the temp. probe.