Obviously you're unaware that the Galaxy S5 supports CDMA at LTE speeds AND GSM at HSPA+ speeds. The Verizon Galaxy S5 is a "world" phone and does not require any sort of SIM unlocking in order to be used on other carriers. (as i can show you with a simple screenshot). However i think my decrease in speeds is caused by a bad tower on the opposite side of town from where I actually live. While at home (with only 2 or 3 bars of service) i am able to get fairly decent speeds without issue. As far as the point of this thread goes i was wondering if anybody had any tips or tricks for better stability of the HSPA/HSPA+ network on the Verizon Galaxy S5 and to see if anybody was able to remove the SIM error without rooting. With rooting i know it can be achieved as i have already researched how to do so. I know why the SIM error is there, I'm not that oblivious. But thank you very much for your comment.