I have a HDS Gen 2 Touch. Been using the built in GPS, marking waypoints, etc. Was wondering if the external antenna would give me more precise readings? The Point 1 or LGC-4000? The only thing I can find is that the update / refresh rate is much faster. I can't find any capability comparison between the built in unit, and the external antenna's.... what are the differences / benefits?
Thanks for any input.