You nailed it. Im one of these guys who TYPICALLY ditches the "old" body style as soon as the "new" body style comes hits the showroom. The obvious caveat is if the newer body style is genuinely uglier, or if the newer body style lacks performance. I completely agree that an IFS or IRS setup would open tremendous new avenues. Look at the Raptor guys, they have a ton of options. The kicker here is that long travel raptor setups cost a fortune. They seem to be on the rare side for a demographic who's truck starts at $55K MSRP before the first mod bolted up. The point here is that affordable mods to reach a certain level of performance may become a bit more elusive. Even with solid axles, performance at the highest levels isn't cheap either. There may be a year or two or three before the aftermarket truly catches up to the point that they can build true hardcore trail worthy rigs, but I have no doubt it will happen.
Aluminum cracking may not be such an issue with Today's technology. I have a 2013 Jaguar XJ that is completely made of aluminum…no issues. Granted you don't take it off road, but all all the new Range Rovers are also made completely of aluminum. I do believe when the Rovers made this move to go to an aluminum unibody, it was for the same weight-savings, tree hugging efficiency figures mandated by the EU and the EPA, but I also believe some more general performance was realized from the seat-of-the-pants acceleration standpoint. We'll see if Chrysler can build a good off-road rig using a budget 1/3 to 1/2 of what it takes to build a Land Rover…. When they pull that off, and when it's practical, the question is do the hardcore guys still like it, or have they merely created a slightly more crude version of the WK Grand Cherokee's/