Re "drop shipping": You could be right about the RT2 comparison thing. I remember in some of the old 1.06 discussion threads they were talking about "drop-shipping", and seemed to think HAAL would help with that. The reasoning may have been that (for example) you could haul coal out of the hills to a rural station on the flat, in an area that still had a $0 price for coal, and then have it picked up by another train that would haul it to your steel mills. I can see the sense of HAAL in RT3 from that perspective, but not having ever played RT2 myself I have no idea how its cargo system worked.
My problem with 1.06 HAAL is that often I want to do something like have an express train haul one or two cars of any cargo, just to keep profits up when express is somewhat intermittent. Naturally I want it to pick up the most valuable thing available for the "any cargo" slot, and run empty if nothing profitable is around, but sometimes it will end up hauling any old crud at a loss if nothing else is available. This reduces speed, burns fuel, and reduces reliability for no benefit. It can also drag away a cargo that I want to stay put. Admittedly it doesn't happen all the time, so I could probably just ignore it when it does happen.
Incidentally, WP&P's additional trackside buildings were an attempt to allow "drop-shipping", so he may also have been influenced by RT2.
Actually, the removal of price islands in 1.06 (part of the ship-at-a-loss implementation) means that resource stacks and consequently industrial production are a lot more unstable.
You think the price islands were removed as part of ship-at-a-loss? Offhand I can't see how they are related. How would that work?