I have the 22 caliber on order. I have the viper 25 cal pistol as well as many other rifles in each caliber. I think the biggest thing for me is that the 22 caliber has the best ammo selections way more than the 25, and also if you want to go with a heavy slug you can get there in 22 caliber to...
I spoke to the folks at New England Airguns today and they told me it is coming with a threaded barrel. I asked because the preorder on there website does have a spot now for threaded selection.