Interesting acquisition announced today....Blackberry to acquire Good Technologies. For those of you who don't know or are familiar with Good, it's basically a BYOD platform for enterprises. (Email, intranet, etc.) Not necessarily directly Sprint related, but many people use both.
I've seen some threads recently about the differences between SIM/UICCs and though posting a compatibility matrix would help people.
This is pretty straightforward. The matrix has every Sprint LTE device, and what UICC card is meant for that device. Mix and matching UICC card types probably will not work, but swapping around UICC cards for devices that use the same type of card should work properly.
Keep in mind, you cannot simply move your UICC card to another phone to use it. Sprint's device authentication system still requires the correct UICC and MEID to be on the account to authenticate properly and work.
Pretty sure they can slowly repurpose LTE portion of M-MIMO to 5G nr so that shouldn't be a problem in the very long run. Just like Clear equipment, and those have served their purpose quite well over the last 6 years.
It is disappointing that Sprint does not have a not Massive MIMO 5G option. I assume the price would be significantly less for less robust solution that would allow for both 4G and 5NR. This would allow more places to have 5NR sooner.