Personally I think the G4 is a better option from a cost and functionality point of view, so I find the G4 the best option for me. I get 30 days out of each and every sensor, and have the Animas Vibe pump for integration, so now don't even need to carry the separate receiver any more. Before getting the pump, I had the xdrip, so also had the data viewable on my phone and smartwatch, but for me, the overriding factors for the G4 are the lifetime of the transmitter (> 12mths), integration with the Animas Vibe, and you still maintain the ability to integrate with phones and watches and share data online if you want (but you do need the extra kit for that unfortunately) if you want