I bought mine in a local shop (StorrarMarine)
Very nice device, especially if you like wreck fishing.
I had an early problem with a connector pin breaking off. Went to Storrar Marine and I just got a brand new unit and now even have some spares double.
The picture is excellent and also the function of marking a wreck on the sounder, which then appears on the GPS plotter. Wonderful.
Downside is that you cannot connect it at all at home. I would wish to plan a trip the evening before and mark it on the plotter. I also would love to download tracks etc onto my IPAD to create a nice wreck base.
However: Excellent value for money on a small boat.
If you dont do wrecks....I would not bother and buy something else, possibly cheaper
In any case, come around and have alook on my boat and see what you think. Alternatively Storrarmarine has a try-and-test unit build up in their shop.