I started with the MOFI4500 SIM4 with an unlimited TMobile business plan through a reseller. Used it mostly on Band 12 speeds usually hovered right around 7-8Mbps.
When TMobile turned on Band 71 I "upgraded" to the MOFI4500 SIM7. I've been able to get decent speeds locked to Band 71, usually 10-14Mbps.
I don't mind spending the money on a better modem/router, God knows I've dumped a ton of money into getting to where I'm at now and am able to work from home without problems.
I do have 4 antennas, 2 parabolic grid, 1 Yagi - 700mhz and a smaller Wilson multi band antenna.
Just looking for some advice from more experienced people.

Here are the results from a Band Scan performed on my MOFI 4500 SIM7.
Band: B2 (Bandwidth 15 MHz Down | 15 MHz Up) Signal: -122 (RSRP) (dBm) Cell ID: 02 (2) LAC: 7BF8 (31736) (310260)
Band: B4(*) (Bandwidth 10 MHz Down | 10 MHz Up) Signal: -112 (RSRP) (dBm) Cell ID: 0C (12) LAC: 9E03 (40451) (311480)
Band: B5(*) (Bandwidth 5 MHz Down | 5 MHz Up) Signal: -113 (RSRP) (dBm) Cell ID: 01 (1) LAC: 0305 (773) (311589)
Band: B12 (Bandwidth 5 MHz Down | 5 MHz Up) Signal: -88 (RSRP) (dBm) Cell ID: 15 (21) LAC: 7BF8 (31736) (310260)
Band: B13(*) (Bandwidth 10 MHz Down | 10 MHz Up) Signal: -97 (RSRP) (dBm) Cell ID: 01 (1) LAC: 9E03 (40451) (311480)
Band: B14(*) (Bandwidth 10 MHz Down | 10 MHz Up) Signal: -115 (RSRP) (dBm) Cell ID: DF (223) LAC: 161D (5661) (310410)
Band: B66(*) (Bandwidth 10 MHz Down | 10 MHz Up) Signal: -110 (RSRP) (dBm) Cell ID: 0C (12) LAC: 9E03 (40451) (311480)
Band: B71 (Bandwidth 5 MHz Down | 5 MHz Up) Signal: -100 (RSRP) (dBm) Cell ID: 3D (61) LAC: 7BF8 (31736) (310260)