I got the Linksys wrt1900ac--if speed were the issue for me, I'd imagine most people wouldn't be able to use the backup feature. Glad you got it working though. And surprised because I'm not the only one who reported a problem with that.I have an Asus wireless ac Gigabit router. I get killer speeds with that thing. That might be why it worked for me.
***Now that I think about it, the last time I tried backup on adbfire was about 5 versions ago. It's very possible it was fixed.
Mastafunk's mod launcher is pretty cool. It just wasn't practical for me because other people in my family like netflix. I created a shortcut in xbmc but found it didn't work well. XBMC ran great and without kfttv launcher the box booted up much quicker.