Gamo Viper Express vs. Shadow DX Express Shotguns

I've found one unit of the "Viper Express" available at Youngs Airguns in Auckland, straight bought it and had it shipped to my local gun store, but when I picked it up today, the gun sent was actually the Gamo Shadow DX Express, not the Viper Express.

I'm still happy as, since both seem to be very similar in all aspects, but still not getting the actual product I was expecting comes with a few question marks. All my research was done on the Viper Express, and I couldn't really find much about the Shadow Express DX on the internet. The two are very similar, with slight differences in the stock, and the Viper comes with a life-time guarantee, whereas the Shadow has only a 1-year guarantee. Both use the same powerplant, but for some reason someone online said the Viper is slightly more accurate. Besides that, there's not much more content available online at all.

Has anyone here got any knowledge or experience with the Shadow DX, and knows in a bit more detail how it compares to the Viper?

I've already emailed them, but so far it seems the two are just the same gun with a different stock and slightly different barrel venting. I couldn't really find any other differences, that's why I asked here if anyone knows. If that's the case I'd be more than happy to keep it - and if I'm honest, I found the Shadow DX stock looks better than the Viper.