Garmin's sounder has been getting better with each new black-box that has come out, and I would definitely say it is worth considering. Some things about Garmin's sounder that might help you decide are:
- Garmin's sounders are very easy to use and most of the tuning is done automatically
- The new digital technology spots the air bladder of the fish, making spotting targets easier
- It can utilize up to a 2kw transducer at 50 and 200khz
These points may also be a negative factor depending on if you want things done automatically for you or not. Furuno tends to have a bit more fine tuning capabilities in their sounders, especially on their commercial side (such as their DFF3 and FCV-295 and FCV-1100). Those commercial sounds can do all the way up to 3kw and have more options in terms of what frequencies can be used. All of Furuno's machines are digital as well now.
I would say that if you are in particular trying to shave along the edges of contours and ride the shelves and the ledges in fairly deep waters then Furuno might be a better bet. However, if you are instead looking for a bit of a easier machine to use and not trying to spend a lot of time tuning to spot fish and get a good picture at shallower waters (say, 300-1800 ft-- still pretty deep!) then the Garmin is a better choice in my opinion.
Of course all of this is heavily dependent on what transducer you are using with the machines. For the sake of comparison let's just say the statements above are comparing the units utilizing the same 1KW B260.
Let me know if you have any other questions. Thanks, and have a great day, | 
