Another vote for duplicating the fit to at least get as good a baseline for comparison between the two bikes. Geometry differences can make a huge difference, as do wheels and tires. Some frames will speak above any component you put on them, telling you what they're all about. Other frames need certain pieces to make the best of them for you. It's part science, part magic.

The Trek is a hand-made beauty that shows its upper Midwest disposition and values. The Ironman is a mass-produced bike geared for fast rides and racing. Greatly differing origins, even if the 930 is a short wheelbase road bike (like the IM) that can run with the best of them. I've spent a lot of time building and thinking and searching for the 'God Particle' when it comes to how and why frames/bikes are the way they are, and have found general guidelines and boundaries, but as soon as I get granular, I find more possible variables. Your Trek is gold, which is the most wonderful feeling. Keep it and ride it forever, and don't worry about having other bikes feel as good. IMO, it's not their fault if they can't, and if an IM doesn't jibe with you, then that's not your fault. You've already won!