I might have a little real world.
But it depends on what "upgrade" you are trying to accomplish. Lower the pedal effort, improve thermal resistance for the excessive load of bad trailer brakes, and for that, I would say you need to work on the trailer brakes as it's not until the recent years that a vehicle brake design has to incorporate for poor trailer performance.
There are several ways:
Alter the rotor swept radius to tire radius ratio; bigger rotors or smaller tires.
Increase the clamping force on the brake pads; larger pistons or changes to the actuation side.
Friction material changes; higher friction to lower pedal effort or higher metallic for more thermal resistance.
Rotor changes in vane design to add more cooling; slots added for degrading friction material, holes added for improved cooling (but only if vane design was altered to incorporate the bleeding off of draw from the hat section, usually not done in the aftermarket).
You killed number 1 with not changing to 450/550 axles, by best take on that adaptation.
Adding larger pistons in the calipers requires changes to the master cylinder, brake pedal lever, and often booster. All that typically happens in vehicle design. A lot of work, a lot of expense.
Friction material changes are the easiest, most cost-effective, and changeable if it's not to your taste. There is aftermarket that is higher friction and somewhat higher friction with higher thermal ability, but higher thermal usually is a trade-off with lower cold friction.
Rotors are a bag of worms from an engineering perspective. Slots work well for one revolution of removing water film, and a good choice if the friction material is degrading and outgassing. You are better off having good friction material for the load. But in order to pass over the slots, the friction material had to be stiff, with no compliance. That leads to thermal banding and some loss of performance, situation dependent.
Holes are primarily a weight savings path. If you take a rotor that has it's vanes designed optimally with solid rubbing discs, adding holes can degrade cooling. And it removes mass so the thermal spike of a one-stop event is heightened. Properly designed, they can help during extremes. And then we have the cracking issue.
OE rotors with holes designed in typically have a radius cast in on both the outer surface of the rubbing discs and cast in on the inner vane side of the rubbing discs. Aftermarket rotors are typically solid disc rotors that have been drilled and radiused, on the outside, but not the vane side. So they can still crack. Guys who produce them with a clue will not put both the outer disc and inner disc holes in the same vane but stagger them as to minimize the airflow disruption from the hat, and to not have cold then hot vane channels next to each other.
There are so many options on brake pad manufacturers and one person's improvement is not another's, so brake discussions get a piling on of who likes what. Chaos. And in the USA there is not much by the way of government rules telling consumers about brake pad performance. If you want to use edge code designation, it's OK, but not ideal by any means.
Having designed friction material formulations for 5 years then managed my old company vehicle testing operations for 25 years, I can tell you every friction material is a compromise to something, fade, wear, noise, performance; there is no perfect material.
A starting point for your journey made be to look to Power Stop Z23 for increased effectiveness. While a competitor, a few of the friction material designers I worked with in my old company went there or to their supplier. They have materials in the GG friction range, a place where OEM will not go. Higher temperature resistance I usually go towards Hawk, an offshoot of my old company before I got there. They are high metallic but depending on the level of pad cold performance suffers, LTS version the least, but it's there.
I don't go to drilled rotors until I would really have to, and I never have. I try to not bandaid the friction material choice. But that's me.
The 2004 trucks were the last year for the Akebono calipers with TRW rotors. 2005 took on TRW calipers which weren't a situation of the Akebono designed calipers being an issue, TRW's pride was hurt when Akebono came in and stole what they thought was a shoo-in for the contract. We have an offer you can't refuse for 2005......
The OE 1999-2004 TRW supplied rotors were extremely thermally efficient with their post vane design, but any replacement rotors won't have that. Not even the Motorcraft service replacement rotors made by Federal-Mogul, who in the aftermarket markets as Wagner. The tooling and manufacture are too expensive for the normal aftermarket, so they are straight vane, same as the 2005+ OE TRW.
Anyway, just my viewpoint.......
Former Vehicle Test Manager, Friction Products.
03 F350SC 4x4 6.0 Auto 5/30/03
YouTube Videos - TooManyToys
Never buy a Ford Remanufactured motor