I'm not up on the 4x4 trends. Here in the mountains where I live, eveyone drops IRS and IFS in favor of one ton axles. My plan is to build a full floating high pinion 9 inch axle for the rear of my truck and high pinion 509 for the front. A 509/609 is using a 9 inch axle and installing the steering knuckles from either a Dana 50 from a Ford F250 (509) or Dana 60 from a F350/450 (609). IFS and IRS use really weak constant velocity joints instead of U joints on the axles. They are weak in OE form. However, I am sure that aftermarket companies have master the art of making them stronger. Also, IFS and IRS only allows flex at one corner, which can cause the vhicle to drag over obsticals. They lack articulation compared to a straight axle. Again, some company somewhere has probably over come this problem.
This pic shows the possible problems with idependent suspension compared to solid axle.
https://qph.ec.quoracdn.net/main-qim...a9997c10ac01-c