Going to order/buy a new boat in a month or so. I know everything I want except for the electronics. Thinking hard about the Lowrance color units. Would like a sonar/GPS on the dash and just a sonar on the front with the trolling motor. Connect them so each unit can use either the front or back tansducer. What really worries me is all problems guys are having with upgrades and new down loads. The lakes that I fish all summer are 10-15 feet, some weeds and a soft bottom. Looking for a good set up. Any imput will be greatly appreciated.

Keith,
I have a Lowrance 27C in the back and a 522 in the front. They do network easily with the Ethernet cable so you can see either transducers signal on both units. It is easy to switch between "sonar source" units and tt works very well. If you buy the X27/28 and 520 combo it would cost about the same as just buying a color sonar for the front and you would have the GPS capability on the front unit which is really nice for staying on reefs and the like. I have seen the shallow water/weed issue and just updated to the 2.4 code and mine is now working fine. Another post said they had no problems with the 2.4 release while others indicate they still have the shallow water/weed issue. I think Lowrance will get to the bottom of it.

For sonars I`d look at Vexilar, http://www.vexilar.com/pages/products/products_all.html
Here`s vexilars new Edge3 http://www.vexilar.com/pages/products/products_lc-507.html

I replaced a brand new Lowrance X510c with a Vexilar Edge.

The Lowrance had issues with locking up and freezing.

Furuno is another brand I`d look at in sonars.

If you want a cheap sonar look at the Humminbird 565.

I have a Lowrance 5200 Globalmap that I do like very much

I agree with Whofan and have the same setup. A Global Map and a Vex Edge 3. The Vex is a great unit, I could rave forever on here about it !

This is a cost effective combo for an excellent sonar vs a Lowrance combo unit. It doesn't solve your desire for two sonars. Fortunately for me I have a Tiller boat so I do most of my fishing in the back. I just use a cheap Eagle Fishmark 320 for $150 on the bow cause I don't use my bow mount that much. That little Eagle works pretty good although it is not color.

Just my opinions.