sonar/chartplotter on bow...which one?

hey guys going to get a debate going. I know its almost like comparing apples to oranges in some cases but i am going to put a new sonar/chartplotter on the bow of my boat and have mixed feelings about what to get. i ahve an eagle 500c on there now but i want a chartplotter. I have the lowrance 520c on the console but my waypoints usually dont do me any good back there. Its going to come down to a Lowrance hds 5 and netowrk it together with my other unit on the console or one of the new humminbird 700 series. Has anyone spent much time on eithe rof these two units? Thanks for all the input ahead of time.

I have a 520c on the bow and one on the console and also a h-bird 997 on the console. I don't have the 2 520's networked together but I just put a mmc card in and transfer the waypoints to each other. If I were going to get a new one I would buy the new Lowrance HD series. I usually upgrade when something new comes out but the 520's are less than 1 year old.