Hi,
Thanks for your comments! These are very helpful. I already created a clone of the default simulation folder, so I am indeed going nuts.

I'm currently in the process of inserting all the apply, release, charge, etc. data from the latest MSTS realism patches. So far my impression in how these 'feel' like in RW is quite good. 30 car loaded coal unit train (default, unmodified cars) + 2 F7s with my mods - from 30 mph on level track to standstill with 30 PSI in the brake cylinders in a whopping 0.7 miles. Plus with an about ten times slower brake application than on the default engines it takes forever until the train even begins to slow, even when I slam the brake valve to almost full application.
Your dynamic brake force suggestion works very well too, it manages to slow the train nicely, but not too quickly on level track and holds it okay on not too steep grades. Please keep in mind though, my only point of comparison for all that is how a nicely tuned MSTS train handles.
I also try to "re-gear" the engines for a new max speed of 79 mph. The default of 100 was also available on the F series, but I think the slower geared ones were more common. 65 was the top speed of most freight units I think, though some railroad used even slower geared ones. What do you think, is 79 a good compromise to use only one BIN file, or should I try to provide seperate Pax and Freight units (more clutter in the asset browser)?
But before I get into that, I need to ask a quick question about the MaxSpeed setting: can I just edit that freely and the game engine takes care of the rest, or does this only work well (read: realistically) when the TractiveEffortVs* curves are also edited (which I wouldn't be able to do, BTW)?
There's more good news: Just last night I received permission from Scott Hoarty to include his three F7 reskins (CNW, GN, CMO) into the update process! Thanks very much, Scott!

Cheers,
Michael