I'm curious about it too. My main reservations would be wrt longevity and shootability.
Given the N frame 44 is not really renowned for its strength, I wonder how the L frame, even if only a 5-rounder, will do. Granted you don't buy a gun like this to shoot a steady diet of the supercharged 44s but I would hope it will stand up to a steady diet of standard factory strength loads. I saw the Jerry M review too and he had some interesting things to say about this so maybe it is a non issue. I guess only time will tell.
On a more practical note for me, I find the 4.2 629 a handful with factory loads and it is a few ounces heavier than the 69 so I wonder if the 69 is noticeably more challenging.