The number of observations with the Mighty Mouse, Lowe Active and Big Brother were identical almost no loss of lock occurred with the external antennas. Next the signal strength analysis. I averaged the signal strength values for each satellite during the observation interval of 1 minute. Then I compared the external antenna average with the internal antenna average, the table gives the additional signal strength of the external antennas. Below I listed my impression of the strong and weak points of the three low-cost antennas.
All antennas show a fairly large amount of radial assymetry with satellites at low elevations.
The external antennas show their advantage when working under sub-optimal reception conditions. If you have a clear view to the sky, don't bother about external antennas. The 12XL's internal antenna performs well. When you have to run your equipment on batteries, the Mighty Mouse is your choice. If you need those extra dB's because of a very long cable to your antenna, or in very dense forest, take Big Brother.