Z3801A Position Survey

I've had the opportunity to run the position survey function on five Z3801A receivers (with two surveys from a few of the receivers). All were fed from the same antenna, and the surveys were done over a period of about four months. Just for the fun of it, here are the lat/long/elevation shown by the five units:

Unit Latitude Longitude Elevation
N8UR #1 39 42 48.849 N 84 10 20.343 W 322.95M AMSL
N8UR #2 39 42 48.902 N 84 10 20.374 W 323.48M AMSL
MVUS #1 39 42 48.771 N 84 10 20.291 W 321.47M AMSL
MVUS #1 - 2nd Survey* 39 42 48.801 N 84 10 20.323 W 324.70M AMSL
MVUS #1 - 3rd Survey 39 42 48.900 N 84 10 20.357 W 321.61M AMSL
N8ZM #1* 39 42 48.799 N 84 10 20.414 W 314.66M AMSL
N8ZM #1 - 2nd Survey 39 42 48.698 N 84 10 20.516 W 323.37M AMSL
WB8GXB #1* 39 42 48.787 N 84 10 20.343 W 315.57M AMSL
WB8GXB #1 - 2nd Survey 39 42 48.738 N 84 10 20.497 W 322.60M AMSL

Average 39 42 48.805 N 84 10 20.3842 W 321.1567M AMSL
Std Dev 0.0688 0.0772 3.5685M

Elevation (outliers removed) Average 322.8829M AMSL
  Std Dev 1.1252M

Surveys marked with a "*" were made immediately after power-on and initial satellite lock. Other surveys were made after several hours of warmup.