Most GPSs in the hobby range and sub £100 price range have around the same accuracy\resolution.
In general the better the GPS antenna the more stable the location and variance in position. There are Ublox GPSs with 25mm ceramic patch antennas than might slightly improve on the Globaltop used by the Adafruit board, but dont expect miracles.
srnet:
Most GPSs in the hobby range and sub £100 price range have around the same accuracy\resolution.
In general the better the GPS antenna the more stable the location and variance in position. There are Ubloxe GPS there with 25mm ceramic patch antennas than might slightly improve on the Globaltop used by the Adafruit board, but dont expect miracles.