I use Google Wallet daily without issue, once you know where the NFC chip is located on your phone it takes seconds.
The reason Goggle Wallet and Apple Pay may not work at some national retailers (CVS, Walmart, Rite Aid,some Home Depots, some 82 retailers in all) is because they have turned off their NFC until their own payment system is launched later this year.
Many small shops don't turn NFC on either because they don't understand it.
Also Google Wallet doesn't require a Secure SIM so don't waste your time trying to acquire one. They were for Verizon's payment system.