WNR3500Lv2 Poor Performance, Slow Wifi drops to < 1mbps

We had an old Netgear WNR3500Lv2 and some devices on the network would barely go over 1 mbps. There this post on the Amazon page
Amazon

YES! I've reported this to Netgear support and all they want me to do is keep sending them proof of purchase information and what not, and not addressing the issue! I had a batch of routers come stock with firmware versions 1.2.0.16_40.0.66 & 1.2.0.32_40.0.74 and both give insanely poor wireless speed tests, barely over 1M. After I installed firmware version 1.2.0.28_40.0.72, then wireless speed tests matched wired tests. Hope this was helpful to anyone having the same issues! see less 
By James B. on July 10, 2015

The Netgear Community forum had this thread on it Netgear

Re: Slow wireless 1/2mbs WNR3500Lv2

‎2016-01-06 10:20 PM

We restarted the router each time. We do not want to go through the trouble to re-configure by a factory reset. We down graded two versions to 1.2.0.28 and got back the speed. You have really got an performance issue for the last two releases!