I've had nothing but trouble with the WRT1900AC. Xbox live wouldn't work, router would reset.
I returned it for the R7000. I'm at 46 days of uptime now with 21 clients connected.
After about 35 minutes of troubleshooting, my issue got escalated to level 3 support (engineering). I should get a call tomorrow. Hopefully, I get a replacement then.
EDIT: They are replacing the router. I expect the new one next week. It took 30 minutes with the second person.
I did a live chat today with Linksys. I am on the phone "level" now. I am expecting a call today or tomorrow. Someone named Jake Taylor (I think overseas) said they are getting reports of HW issues.
Were you able to get a replacement? I saw your comments on various threads.
I am unable to get the 2.4Ghz band to work. Once a device connects (laptop, Xbox 360), it drops connection instantly. Only 5Ghz,and hard wired work.
Any suggestions?