As different devices will have different strategies and formulas to calculate 'max speed', it is quite understandable and normal for these to value to be different. Heck, my Velocitek ProStart reports two different values for MAX at the same time!
But different steady-state readings are different. Assuming a good antenna position for both and and un-occluded view of the sky, both units should read with a few 10ths over a 10 second average. If that is not the case, something strange is going on.
But different steady-state readings are different. Assuming a good antenna position for both and and un-occluded view of the sky, both units should read with a few 10ths over a 10 second average. If that is not the case, something strange is going on.