While this is a good GPS for standard measurements, as of today the interface doesn't display the accuracy in real-time for a tilt measurement (with IMU initialized) and accuracy can be bad, way above the claimed 2.5 cm when GPS signal is not so good, even if displayed HRMS and VRMS are good. IMU tilt measurement accuracy is kind of unknown on this device, depending on multiple factors (tilt angle, number of satellites, obstructions) which make it too risky for survey-grade jobs (especially in urban areas), which need global accuracy displayed in real-time. Also, the IMU initialization has proven to be erratic, getting stuck for a long period of time, especially when number of satellites is low. The IMU tilt measurement functionality just won't start sometimes. This is my experience in urban area. In open area, you might have no problem. My advice is if you don't need the tilt measurement functionality, this is a great product, with an incredible price. But if you need the tilt measurement function, in my opinion, this device is not mature enough for survey-grade jobs as of today.
