We have a Verizon 55+ unlimited plan in Texas. It is unlimited everything, including data. We can stream to our phone and cast to TV, generally without a problem. However, if you use the phone as a hot spot it is throttled to 600Kbps - note the kilobits, not megabits.
On our travel this summer, we used ATT hotspot with service/data from OTR Mobile. I was pleasantly surprised by coverage and data rates across TX, AL, MS, TN, KY, IN, IA, SD, WY, ID, MT, UT, NM. Out of 72 days on the road, we only had about 6 days with data less than 10Mbps. We were in many small towns and out of the way places. In many spots we had better ATT coverage than Verizon. YMMV.