What network should I be set on LTE/CDMA or
Cdma
It depends on if you want to restrict your phone in certain ways. When set to LTE/CDMA your phone will be able to use either LTE or CDMA, but if you set it to only CDMA then you will not be able to use the faster LTE network (which also might be available or work better in certain areas then CDMA by itself). If you're worried about your data limit using CDMA will transmit slower, so you may do less over it, and use less data.
If speed and connections are important to you then changing to the network with the most options should work best for you. If you have Global as an option too then I'd recommend using that. Some people have stated MMS sends faster when set to Global over the other options. Additionally others have said having Global set leads to less time that the phone is searching for signals. A person in Texas reported when set to LTE/CDMA his/her phone would search for a signal for up to 2 minutes when switching between towers, but when it was set to Global it took 10-15 seconds in those same areas.
On my old phone (a Samsung Stratosphere) it only had the LTE/CDMA, and CDMA options, and their would be times when my texts (and/or picture messages) didn't go out (staying in pending status), and times when it would say pending and actually have sent. With my new phone (a HTC One m8 set to Global) everything sends right away. I also find places were I encountered low signals, or slow connections with my old phone seem to be connected at 4G LTE, have stronger signal strength, and faster speeds with my new phone. While the phone itself, the texting app (default on the old phone, but Verizon Message on the new), and other things (Android version 2.x vs 4.4.2) may have been factors in the issues I believe the Global setting is a big reason why things run so smoothly and quickly now.