Verizon recommends using MIMO antennas because their 4G towers have at least two MIMO antennas. If your modem has two MIMO antennas as well, you may benefit from reduced signal reflections, more reliable data reception, and an increase in bandwidth.
While Verizon’s language indicates that MIMO antennas are required because they want to offer the best service possible to their users, technically, a MIMO antenna is not required for any of our products, including the CR300-CELL210 (which does not have a diversity port) and the RV50X and CELL210 (which do have a diversity port to accommodate MIMO antennas). Our users have found that a single antenna works well without noticeable issues.