I've been seeing issues when using the 5GHz SSID on my WiFi (Apple Airport Extreme, 802.11n). If I switch to the 2.4GHz SSID, it works fine. So I am wondering if there is some issue using the Surface Pro 3 with 5GHz.
I rolled back to the original driver yesterday with no issues. In an experiment last night I updated the firmware on my Asus router and reapplied the firmware update to see if that would help. It did not. I still had occasional limited connections. I just rolled back to the original driver once again. This is using 5 GHz.
It sounded like this new power save mode in new version of wifi AC band is not compatible with Apple Extreme. I actually have the very same router as my secondary at the basement. I might have to try that.
I also suffered this issue this morning waking the SP3 from sleep. My Bluetooth mouse was not functional and I could not get connected to my WiFi in the house (2.4Ghz or 5Ghz). I went into Device Mangler and just rescanned for hardware and poof! In popped the wireless adapter and everything started working again. Not a good deal, but seems like something that they should be able to easily resolve with an update.
I didn't try disabling Webroot but went for the full restore. I reinstalled everything except for Webroot. Seems like my Wifi and freezing problem is resolved for now. I really hope it's not Webroot. I'm going to use this for a week to see how stable it is then I'll try reinstall Webroot again.
I had random limited connection issues with the WiFi. I uninstalled the wireless card drivers from device manager (I also selected delete the driver software for the device) then scanned for new hardware to load the original drivers. No WiFi issues since. After installing the old drivers I received an update for Windows. Running the update loaded the new drivers again so watch for that. The update is called System Firmware Update - 6/19/2014
I tried this and it appears to have worked for me. I bought a SP3 (i5, 128GB) on its release day. It worked great all weekend and I installed a TON of stuff on it, including Visual Studio 2013. In addition to uninstalling the WiFi Device and Driver Software (as described here), I disabled Hyper-V (which was installed/enabled because of Visual Studio 2013). This seems to have fixed my issues. What a shame that such a great piece of hardware has such a hard time getting online. I absolutely LOVE this device and the keyboard CRANKS compared to my Surface 2 with Type 2 (love the new touch pad). Here's hoping Microsoft hears us and fixes this one issue.