A representative for the company in the forums states that they have heard the cries of consumers, mainly due to the buggy nature of the early builds for Lollipop, and to help owners, they will bring Android 5.1 as soon as possible.
As part of the SHIELD tablet experience post-OTA 2.0, we heard your feedback about performance and responsiveness issues related to the Android OS. We have identified and fixed many of these issues in an upcoming OTA release, which will also upgrade the OS to Android 5.1. In addition to new features and improved security, Android 5.1 provides an overall snappier end user experience.
This is great news for SHIELD Portable owners, as their devices have still yet to even get a taste of Lollipop. If you are like me, running Lollipop on the SHIELD Tablet, your experience is likely filled with frustrations from time to time, including a very odd Netflix bug which renders the app useless unless you reboot the device.
Either way, the OTAs should arrive soon enough. We will let you know when to start hitting the update button.