Basically comparing it to the Viltrox shows how much can be shaved off the size and weight when going all the way with the electronic corrections (since the sharpness of the two lenses is almost the same - with a little edge to the Viltrox - but the infamous D and V are decidedly different, and not in favour of the Sony).
I'd probably still get the Viltrox (which I hopefully will do, someday). 300 grams vs. 550 is not a deal breaker - after all, it's less than a soda can. It could be one for someone putting the lens on a drone but I guess that's about it.
