I'm not all that impressed with the Big Boy Whistle either, but what I noticed also happened between the old SR,Frisco type Mountaini Class's between the old ones in ithe DLS, and when the Mountain Class's were introduced into TRS 2010, going by the previous copy Ihad of that, is that theiri whistle sounds were also nowhere near as good as it used to be, and now in TRS 12, the Mountain Class comes up as a dirty big Red Mark in the CMP... you can't use any Mountain Classes at all in TRS 12, it is impompatible.... so too is the SAR 520, unless you go to the DLS and or copy all lthe dependencies from TRS 2010....I've had it running in 12, but coming from TRS 10, you have to muck around fining missing dependencies....
Another thing from TRS 2010, as I found when I had TRS 2010 before, is that the SAR 900, the OB (non tarped) gondola is not compatible with TRS 12....yet the tarped version of the OB gondola is OK, and if anythin,g comes up as a 'Warning'(Gold Exclamation Mark in CMP), so somewhere between TRS 2010, and TRS 12, something has gone terribly wrong... I am looking forward to the next TRS to see if all these errors are eliminated, and that we can all go back to being able to have them all working nicely like they did in TRS 2006