We have a Dexcom G5 and use Xdrip to read the data directly from the CGM. It has a number of benefits over the OEM provided readers: -no forced replacement times for sensors. -No forced delayed starts on new sensor insertions -predictive algorithms and treatment recommendations. -more integrations into third party systems (like IFTTT) -Opensource community project that keeps evolving much faster than the OEMs
Nightscout is a cloud service to store data reading and treatments. Again its community developed opensource solution which gives you complete ownership over your data. Some of its earlier game changing features are now common in the OEM solutions, but I still like the idea of owning this and it being opensource. Nightscout is a really big help for us managing our son (whos 6) since it makes it really easy to give real time access to his CGM and treatments to anyone anywhere.
Nightscout is also the unofficial hub for the Opensource development in diabetes. They've contributed so much that is now being used by OEMs. Im a big supporter.