A quick update – as of now, it works but for a problem with the LCD display… and despite checking wiring, etc., (BTW I’ve done loads of these…) it still is not working. Even tried a different 16×2 display of my own stock. But the good news is that I have the heater working, extruded some plastic, and all 3 axes are running smoothly! So it should not be long before the first build, and obviously the LCD has no bearing on getting out a print.
I already am looking at added a heated bed by routing out a piece of MDF to support a MakerBot ThingOMatic unit. I have all of the MakerBot parts ready to go. However, another power supply will be needed to manage the heated bed current consumption. Thus this will be something for later.
Like some others’ experiences, if the fan is running the extruder temperature doesn’t get beyond 160C but as soon as you turn it off, it quickly goes to 200C and stays there, even with plastic being extruded. I have a “first generation” extruder design. I do have some ceramic tape insulation that I think I will try before I go to something where the fan is controlled by the RAMPS board in some fashion.
For those of you waiting for the last build instructions, please be patient! In testing I found some issues and so as I have said before, I do not want to release a set of instructions followed by a long list of “oops” and exceptions.
Renaissance Engineer 
Yeeeeahhh good to reed that! And my advice, i’ve got a TOM and to don’t use anymore the ABP, don’t find it useful. the better thing i like for my build platform is an aluminum bed on the heated build platform fo better print!
the display problem might be related to the wrong contrast voltage, try to solder a 10k from GND -> 5V with the pin wired to pin 3 from the LCD (VO – contrast adjustment). when powering the arduino from the 12V source aswell the contrast voltage is too high and the display is barely visible on mine 😦