These are plots of test data I took recently using OpenSource GPS software and Doug Baker's GPSRF hardware.  The data samples are taken at 1 minute intervals.  This represents about 52 hours of data.  

Height above Ellipsoid data

North/East Scatter Plot

Receiver Clock Frequency Error

Vertical Velocity Error

Horizontal Velocity Error

DOPs During the Test

2D Horizontal Error Distribution (CEP ~ 2.4m)

3D Error Distribution (SEP ~ 4.5m)