Autoblog does address the live axle issue this way:
For the most part, the live axle configuration of the S197 is among the best of it’s type ever created. For a relatively simple hardware configuration, Ford engineers did a great job sorting this one out. That’s not to say it’s perfect. There are limits and the GT500 does exhibit some axle tramp under maximum acceleration.
The fact that the last Cobra had an IRS and this one (or the equivalent) doesn’t, despite variants priced as high as $80K, tells me the new one is pretty much crap anywhere but on the dragstrip - especially in the real world of potholes and uneven surfaces.