Ps a picture of one of the installs...
Hang on a sec, I watched a RP install YouTube video just two nights ago that featured a Kato SD40-2 with that exact piece of fibreglass board and styrene under the LM in it! Busted?
If so your video isn't shabby either.
Back to the topic, those Atlas turnouts are really sharp, I don't think I'd recommend them for 6 axle power if I saw them in person though I can't see any way you'd get a short as they are not power routing, unless the wheels of the loco's overlap to the opposite rail at the frog like Bill's experience with the Peco turnouts. It's not easy to make out if that could happen from the blurry "enlarged" picture on the Atlas website.
Dismissing the short theory for the time being voltage drop within the turnout could be the problem. A bit harder to measure "live" on DCC than plain DC so with the track power off measure the resistance between the outer rails and the inner rails with a multimeter, it should be virtually zero. Also, do as I mentioned earlier and watch the LM info screen on the HC while traversing the turnout and see what it tells you.
As to turnout brands, well that's a can of worms right there but in this country (not the US) Peco is very popular and their Code 83 line is gaining a lot of popularity in the US as well. They don't have anything as sharp as Atlas in the code 83 range (I think the sharpest is a #6) but
your loco's and rollingstock would probably thank you for that. As to expense, yes I imagine the range is just as expensive in the US as it is here which is quite expensive. Another brand that's possibly worth looking into is the new range by Walthers that they are doing after Shinohara pulled out of the market.
- Tim