@Arion Hi

Did you ever get an answer to your question regarding the differences between MR6400 and MR150? I have the same question.. PLerase let me know
Thanks

@sherewarrior 

No, I haven't. There's no info about any difference in hardware. MR150 seems a newer product or it's just a marketing decision to rename this same product with a more logical model number in the MR range.

I can tell you, whichever you choose it will work just fine for one or a few devices connected but - probably partly due to the ISP's obscurous algorithm - it can't handle dozens of simultaneous connections even just via LAN port, so it's unrelated to wifi performance.

@Arion 

I feel it's just a software update, and they decided to create a new product. I have compared products data sheets (the only place where I found some differences).

1/ MR100 (not in MR6400)

-Wireless Schedule 

-2 LAN ports (other 4)

SW specification difference:
· DHCP: Server, DHCP Client List, Address Reservation
· Port Forwarding: ALG, Virtual Server, Port Triggering, UPnP, DMZ
· Dynamic DNS: DynDns, NO-IP
· Security: IPv4 SPI Firewall, IP and MAC Address Binding
· Administration: Upgrade Firmware, Factory Default, System Log, Diagnostic Tools
· Management: Local Management, Remote Management

2/ MR6400 (not in MR100)

-button to turn off wifi

- has parent control

-you can manage router from their mobile app

SW specification difference:
· DHCP: Server, Client, DHCP Client List, Address Reservation
· Port Forwarding: Virtual Server, Port Triggering, UPnP, DMZ
· Dynamic DNS: TP-Link DDNS, DynDns, NO-IP
· Quality of Service: WMM, QoS
· VPN Passthrough: PPTP, L2TP, IPSec
· VPN Server: PPTP VPN, OpenVPN
· Access Control: Parental Controls, Local Management Control, Host List, Access Control
· Firewall Security: DoS, SPI Firewall, IP and MAC Address Binding
· Management: Access Control, Local Management, Remote Management

The biggest stupidity is that MR6400 currently has 5 versions, and each time they switch antennas purposes - external/internal antenna once WIFI, once LTE.

V3/APAC: 2 Internal 4G LTE Antennas
V4/V2/V1: 2 Detachable 4G LTE Antennas

3/ MR100 vs. MR150

- 150 has 2 more LAN ports 

My biggest concern is if there is a difference between the external antenna gains MR100 and MR6400. You cannot find this information anywhere...