As it relates to RW service…you do need a SIM card regardless of whether you are on CDMA or GSM. Due to the activation flow, you cannot directly activate using an RW CDMA SIM card if you buy your own phone.
In this context, GSM SIM Card implies that your cellular access is provided by RW’s GSM partner.
while CDMA SIM Card implies your cellular access is provided by RW’s CDMA partner. Depending on their respective coverage in your area you will need one or the other… in some cases both may have good service in your area, in which case it would just be a matter of preference. Just as one reference point, your existing Moto X1 coverage is provided by RW’s CDMA partner.
Sorry I don’t have any data on idle battery drains/hour… they are used by two family members that have completely different usage patterns…so I cannot do an easy comparison of battery life but both are happy with their phones…so I can safely assume that battery life is not directly impacting their phone usability…cos believe me…they would let me know if it were :-). My Moto X Pure which was my first phone on the My Choice plan is starting to exhibit reduced battery life.