Mark, honestly both are pretty equal in reliability, accuracy, and quality. It mostly comes down to Wich one you like better. Both are fine pistols. If it was up to me I'd save the money and use it for ammo. Hope this helps and good luck with your choice.

Mark, I have two Gx4's an a Shield plus and like them equally well. The price point of the GX4 is hard to beat even for the Shield Plus. Just follow your gut and pick your poison. You will be satisfied with either. Cheers and stay safe!