I have owned four of them over the years. Two of them were great and two were pieces of crap. I currently use my oldest one which I would guess is about 13-14 years old. It still works, but has vertical lines through about 1/3 of the screen. My second one was a gift from a friend about eight years ago. It worked great for about 5-6 years but finally quit working, probably from bouncing around in its protective case on too many 4-wheel drive trips into out of the way lakes in B.C.
I bought a 4400 model 2 years ago and it quit functioning properly on tie second time I used it. I returned it to the factory, and it still malfunctioned when they sent it back. I sent it back and they sent me a new 4400. It malfunctioned in the same way shortly after I got it.
Last year, I bought a simpler model, the 2202. It will not give an accurate depth beyond 12-13 feet no matter how the controls are adjusted. It is worthless to me.
I talked to the guy at White Elephant who is the depthfinder guru. He admitted that the Bottomline units have had real quality problems the last few years. The older units were more reliable. He also said that Hummingbird has completely reworked the units and the new ones (110,120, 130, etc) have just hit the stores. I am going to wait until a few of you guys buy the new units and report that they work well before replacing my 14 year old unit that is getting hard to read because ofthe gradually increasing number of vertical lines in the screen. I love using it on my Super Fat Cat.