You climb up into this huge locomotive and the first thing you notice is the thrum or the twin engines. Yep, that's right. Two 3300 HP diesels. And yep, it does kinda sound like you're hearing two engines.
Here's a few things to keep in mind. Despite having 6600 HP it will not pull like some of the new engines. It does not have the tractive effort of them either. It really can't lug up hills below 23 mph or so. As it's geared higher for speed the ameters are buried well into the red. However it does have speed. Few large diesels can make 90 mph!
Don't bother with using the dynamic brakes going downhill with a heavy consist though. They're nearly useless. They do work, the ameters say they work. When you apply them there is a shudder in the locomotive like they work. Even the fan on the top that cools the resistors works. But then you realize you're still gaining speed! This is my single largest complaint about this locomotive as I love the routes with mountains. The normal air brakes do work well. They apply very fast. (while I'm not pro, I suspect unrealisticly so).
Another lesser complaint - in fact I'm not sure I'd really care to be honest - is that you cannot couple it to a "dead" locomotive and have it work. This is true of a couple of other DTM locomotives. Any other engine works fine. No clue what causes it or why but cranked up at notch 8 it'll do all of 2 mph pulling a single dead engine behind it.
Here's what I see as the pros and cons:
+ It's a DDA40X. A Big Jack. This is good.
+ In general the sounds are very good.
+ With the exception of the speedometor, the interior is good
+ The exterior is excellent.
+ Realistic simulation of the voltage switching as the locomotive accelerates. (It feels like it shifts gears).
+ it comes with three different models to fit virtually any scenario you wanted to make. One that is older looking and weathered. One that is less weathered and has a couple of different things changed.. horns on top in a dif spot etc, and the third - how 6936 looks today including the air conditioner that was installed on top of the cab.
+ Lights on the outside light up - such as the number panel - with switches on the inside.
Now the not-so-good:
- The braking on the dynamic brake is attrociously bad.
- Part of the speedometer is hidden by another panel. Very annoying for anyone who doesn't want to use the HUD. You can see this in a screenshot above.
- It will not work when connected to "dead" engines. I believe if you put another locomotive between them it does work however.
Despite the fact that I see the dynamic brake as a massive fall back I'm going to recommend it - but get it on sale. First, it may be that it is realistic, tho two SD40's provide much superior braking force and should be approximately equivalent. Second, almost everything else about it is very good. Coupled with the fact that it's an iconic American engine it's an excellent addition to anyones collection.