RT-N16 ( FW 3.0.0.3.108 Test )
UniFi test based on official FW 3.0.0.3.108 --> IPTV, internet & Download Manager all work perfectly
Refer HERE for UniFi setup for this device.
Wireless
I setup the wireless as follows

Test download huge file from NAS wirelessly :
Run Speed Test result:

Can get stable around 9.4~9.7MB/s based on my Acer TM8371G laptop, result similar to previous firmware 102, so far so good ! 
USB - Download Master (AKA Transmission)
I format a USB external 2.5 HDD on ext3 filesystem, insert to the device able to detect without any problem

Click Install the necessary application

Click on the HDD again

Wait for the installation process to complete ....


Installation completed

Click on the Use Download Master option, re-enter the device login ID & password

As usual, I prefer to set down/up load limit to about 450KB/s

Grab few new torrents from the net and start torrenting !


Click on the torrent to see more information as follows


Full speed all the way no problem !



I noticed the Transmission on this build it's more responsive & seem to be faster, nice !
Tested for about 15 hours mostly on WiFi & Download Master without any problem




This firmware is good to go UniFi, enjoy ! 
.