Not familiar with the Lowrance, but I have heard good things about them. I have a Huminbird 180 PMax that I use on my boat, it has a black and white image. Haven't had any problems with it at all, I basically wanted something simple that would give me water temp, depth, and a decent description of what the bottom looks like, and wouldn't burn up a lot of amperage to run it.
This little 180 does it for me. I can run it for a half day fishing trip and it doesn't hardly use any juice at all..... nice little simple FF/DF..... If I had been looking for GPS and a color screen no doubt I'd have done something different, but for what I do with it and what I wanted it to do.. it does what I want just fine.
I heard that the 160's and 170's are very dependable too, and these little units are not too expensive either. I just boils down to how much technology you need and how much your willing to pay for it.....I like mine so far.