Mine works better with the 8.1 Preview but only goes online instantly on Tuesdays and Saturdays. Any other day and I have to wait a few moments on the lock screen and tell it to reboot about two or three times. In all cases, it shows the network connections but if I don't wait and try to force it to connect, then it says there are no connections available even though it shows 5 bars.
No, that piece of junk is unreliable and I use it as a weather station when I do get it online. it is a shame since everything else on it works perfect. Bluetooth connects to anything and I had gotten the type cover for it along with the Microsoft Wedge Mouse and both of those work perfect as well. Just cannot rely on it to connect. The adapter works perfect. There is still an issue with the Marvel drivers and Marvel has to fix that. They are the one's who wrote the drivers, not Microsoft.
The trick of uninstalling the driver and rebooting the tablet no longer works with 8.1 Preview. It did in 8.0 though.