Hi Nyco and welcome. There are no difference in build quality. Only the difference of where each is made. Some folks just prefer Austria made models from the original birthplace of Glocks. Cheers, stay safe and enjoy!

6 of one, 1/2 dozen the other. No difference at all except location of manufacturing.

Hi Nyco, the difference is 4967 miles, proof marks, USA vs Austria on the slide. 6 digit serial on Austrian version vs 7 digit on the USA product.
The Glock USA pistols have American made frame, slide and barrel. The rest of the components come from Austria. All materials for manufacturing the frame, slide and barrels come from Austria and shipped to the US facility. There are no material procurements in the US. Glock Austria keeps 100% quality control of every aspect of production.
Stay safe & have a great day!