Hick, I would take a gen 2 426 Hemi block all day. Note I said gen 2. Proper selection of block, internals, and assembly would be able to make more power that would stay together, yes including the most robust gen 3.
I know the focus of this thread is on the new gen 3. I would not turn my nose up at a gen 3 aluminum 426 Hellaphant block if all the internals, bolt ons and money were readily available, both of those can be hard to come by. And yes aluminum can be tricky to deal with, and special precautions need to be observed when wrenching on one.
Edit, I meant to include a modern day version of the gen 2 hemi block, depending on the variant/selection block, they can handle absolutely gobs of power and stay together if careful selection of parts, quality machine work, proper assembly are used. I dare say the power ceiling would be much higher than the capability of gen 3 hemis on steroids.