OpenWRT is WORKING on the wrt1900ac!! Don't return that router yet! Give it a try!
First off; HUGE gratitude to @Chadster766 for making this image available!!!! Seriously, thanks!
I was just about to return my "second" wrt1900ac and go to an ASUS.
My story (if anyone cares):
Dual MoCA bridge with fantastically awful Actiontec router.
Set top Box that refuses to work with the linksys software. I've tried everything, MTU, QoS, exclusions, etc. VoD will not work with the linksys router and I lose connectivity randomly.
I've been using an older wrt54gl router with openWRT and it's been absolutely rock solid. It's secure, does what I want it to and just works. It's brilliant. It's also very outdated and I cannot get the speeds that I now have available to me. Time to make an upgrade.
Enter the wrt1900ac and the awful linksys firmware. Decent GUI, but abysmal network performance. I have dropouts, cannot run FIOS video on demand and the wireless is frequent to dropouts.
I'm on my second wrt1900ac as the first one kept dropping connections and rebooting.
The new one with the same linksys software was more stable, but is still giving me the same issues, especially no Video On Demand.
I didn't care about the LinkSys software, just the specs and the potential "OpenSource" availability (even if it was slow coming and still doesn't have the wifi opensource headers). I see that many folks are returning their wrt1900ac, and I was JUST about to (return my second one), then I started to download the opensource software and was about to compile my own when I saw Chadster766's img file.
I gave it a try and it worked! I did encounter a bunch of issues, but after tweaks, setting changes and reboots it works fantastic!
Cannot thank you enough. Saved me all that kernel compiling and the plethora of mistakes I would have made.
Give it a go!