Originally Posted by The Golden Boy

I don't think you're wrong at all- in fact- if the market is any indicator (which it usually isn't), stiff bikes have won out over compliant bikes especially as far as tourers go. Even by 1990, my Miyata 1000LT is much more stiff with Splined Triple Butted tubing- which is nothing like the 531C double butted tubing (the 720 tourer never came with triple butted tubing).

I haven't hauled the loads you have- and I'm somewhat smaller- but I can totally see where the long rear end Trek geometry combined with lightweight, compliant tubing could be a nightmare. And I do think my Miyata would be a better heavy load hauler- but I do think my Treks have a wonderful unloaded and lightly loaded ride.