I just came across a deal I could not pass up on a 595c with Gps antenna. My question is are these units as bad as the ones with SI about the slow response on the GPS? Also does anyone know what units I can network it with? ON the GPS puck there is one wire coming from the puck to the plug and one wire coming out of the plug that is capped off. Is the wire that is capped off the one you use to share the GPS puck and network the two units? Thanks for your help..