@ Bushwalker8,

Perhaps you should research the Garmin GPSMAP 65 and GPSMAP 66sr (the models the OP was asking about) before posting misleading and incorrect information.

These new Multi-GNSS + Multi-Band models from Garmin have many of the features you suggest are only found in 'Pro Grade' gear, including exceptional multi-path rejection and real-time on device atmospheric corrections.

Do you really believe that a device that only requires 4-5 satellites to calculate an absolute position would actually use signals from SV's located at or near the horizon when it has access to a couple dozen additional SV's that are in far better positions for horizontal positioning?