@KimcheeGUN thanks for the reply. I understand these are not meant for achieving top speeds on a single device. I plan on deploying several throughout the house to achieve range, separate vlans for private use, cameras and the multitudes of home automation devices, vpn, etc... However, before upgrading the rest of my devices and buying more access points, I wanted to verify there's no issues with these. I've already had to rma the first one I received due to power cycling issues (faulty PSU within the unit), then I received this one and had speed issues, so I wanted to check if it's just problems with the units I'm receiving or a common issue, which as mentioned in the previous post might be an ongoing issue. I haven't had any stability problems as of yet even with over 100 devices connected to the single ap, it's been pretty solid. But just find it odd that I'm having these issues while others report much faster speeds when I checked reviews. Even tried on other client devices (granted all are wifi 5 2x2 or 3x3 mimo, as that's what I currently have).

Edit: client devices, not client services

KimcheeGUN wrote

Here's the kicker...  These are SMB/Enterprise-rated APs.  These are not BUILT or programmed to run up and down a speed test site.  AND OR for single-user maximum speeds.  These are access points are developed for stability under high client load.  If you're physically getting 400mbps, your negotiated air time speeds are probably around 800-900mbps.  There is a difference between real-time air time speeds and negotiated air time speeds.  You can wonder where the advertising is leaning too.  

That is one of the biggest loads of half-truth and glossing and copping out over I have ever seen, are you sure you don't work for tp-link's PR department?

Again this is a common issue amongst many users with the 660HD, it has been shown that they do not correctly use mimo with clients thus cutting their maximum speeds to about half of what they should be.

Also if the environment was that bad how come the upload is so much better than a download when on pretty much all other wireless setups it's either about the same or opposite.

Also the fact that one device sitting right next to another can correctly get a 2x2 MIMO and the appropriate speeds again that's not an environment issue that leads Credence to the MIMO issue and yes I know different devices perform differently but when it's one very very small subset of devices that are able to perform correctly in a vast majority of them are not leads the common problem generally being the access point. Reinforced by the fact that if you take those same devices and put them on a competitor's access point they get the appropriate speeds in the same environment.

Bottom line is this 660HD has a clear performance problem. And claiming that it's designed to handle more devices at once doesn't hold up either because if you're stuck at SISO you're taking up more air time for the same amount of traffic and not able to achieve the total throughput that you should be able to.

Devices linked at 1.2gbps (80mhz 2x2 MIMO) in a clean environment with about -98 noise or better should be doing far better than 300-400 megabits per second, but why does that look suspiciously like and close to the performance you would get with a 600mbps link rata, I e. (80mhz 1x1 SISO).

If you are unhappy with the performance try contacting the online support and reference this ticket. I have found a bug (feature) previously and only got it confirmed via online support.

I chose tp link for the price and decent performance and you can host the controller locally or can even try it without a controller. At the end I went for multi-wan router with failover and wifi 6 wall PoE AP. Is it working  - yes, does roaming between rooms work - yes, is it stable sort of. Was running for 2 months without issues then it just sometimes decides to readdapt a device. 
 

I don't know if ubiquiiti unify will be better but I know people swearing by it. However last time I looked it was twice the price for the same devices on paper.  But I have a nagging feeling after knowing everything  I know now (debugging and investigating some erroneous issues) I might have been better off paying double and avoid some head aches.

  @Napsterbater 

I was just showing that not everyone is experiencing the mimo issue, or other speed problems.  Like most things when it comes to online, people having problems are far more likely to post in various places than those not having issues.  And if you look at post patterns and IPs, you'll see that a number of the posts are from the same people. If we were having the mimo issues at work (where there are hundreds of 660HDs deployed) or if I was at home, I'd not be seeing the speeds I'm seeing.