Hey there! I got mine a little under a month ago, and when I first received it, I was less than impressed, regarding the variation in case length. Originally, on my Dillon 650, I was using a Lee Universal Decapping Die in station 1, with the Trimmer and trim die inserted into station 4, set up to full length resize (as confirmed by a gauge), and trim. Variations in case lengths using this setup were plus or minus 7 thou, or there abouts (this was for .223, so as low as 1.743 all the way up to approx 1.758 or so. Not too huge, but wanted it tighter.
After doing some reading, I swapped the lee die out for a full length resizing die, and installed it to decap, and FL resize MOST of the way, but not all. I find the trimmer to be INSANELY accurate now, and am super happy.
With regards to the heating up of the motor, I have yet to find a resolution for this, although, I find if I run for half an hour, I am out of brass to trim anyways, and can find something else to do while the trimmer cools down. Others on some different forums have talked about opening up the vacuum shoe which fits around the trimmer die to allow more air flow when the trimmer is on, but have no experience with this method.
Hope this long, drawn out, explanation helps a little bit!