The big P30CHs had the same truck as well as I recall and were very rough riding locomotives.
The issue with the SDP40F is complex and in many ways more of a political issue for Amtrak at the time over anything else. They had a perfectly acceptable locomotive adapted for passenger service with a lot of bad press. The F40PH arrived and subbed for E8s and SDP40Fs during a particularly harsh winter and management made the decision to dump the SDP40 as a result. The remaining E8s were always on borrowed time as it was.
It should be noted that the SDP40Fs traded to ATSF for what I recall were CF7s (someone can correct me please), performed fine in freight service with no real issues.
As for a model of the SDP40F, my El Cap set could really use some. However, need to get the E60's reserved up first and built.
