I've recently set up an MW6 kit at a family friends place, and they mentioned that it was sluggish when uploading attachments etc.
I ran a few speed tests, and sure enough, almost every time the upload speeds were only hitting about 2-3Mbps (on a 50/20 connection), and maybe hitting 20Mbps about 5% of the time. The download speeds hold up fine.
As a variable, I connected a notebook directly to the ISP's modem, and pretty much hit 20Mbps upload every single time.
All the AP's have the green LED indicator (good connectivity), and it doesn't matter how near or far I get to any of them, or which device I use to test, the results are the same.
The firmware is also up to date.
Is this a potential limitation to the MW6? A bug with the firmware? Or possibly a dud kit?