In comparing the Godwyn pattern weapons and Gowdyn-De'az pattern the context of the De'az being locked only to Adeptas Sororitas is important to remember. So even if they were just a straight upgrade then it wouldn't be a case of power creep, because it's locked to one background, and any power changes could be addressed in the background if necessary. It's also important to note the flavour, these weapons are meant to be superior in every aspect to regular bolt weapons.
So first, there's a lot missing like the Sarissa:
"This pattern of Bolt Pistol is designed to make use of the Sarissa as an attachment. The Sarissa is a vicious, curved, bayonet-like blade that can transform the Godwyn-De'az Bolt Pistol into an effective close combat weapon even as it retains all of its ranged functionality."
Secondly, the rarity of them makes no sense, why are they harder to acquire, they can only be acquired by Daughters of the Emperor so it doesn't make much sense that it's harder for them to acquire since Daughters don't use Godwyn pattern weapons.
http://i.imgur.com/UldElhd.png
First off, they're all reliable, so this is a good thing, but it means Good quality doesn't matter for these unlike other bolt weapons.
Secondly they're all lighter, this is almost completely irrelevant, almost no one cares about weight in that minutiae as far as I've seen and a few kilos rarely makes a difference.
Third, they all have worse range apart from the bolt pistol. This is potentially completely irrelevant too, but considering most of them are round numbers even if you don't use maps people are likely to say "they're 150m away" not "140m away".
Big problems are the loss of a bullet on the semi which is pretty much huge. Other than that they're basically identical, if they wanted to be boring they should have just reprinted the exact same stats and given it reliable for only 1 rarity increase instead of 2 rarity, however even that is just so boring. Reading these weapons I don't get the feeling they're completely superior to the usual pattern at all, in extremely rare cases maybe?