Hello, I'm in the market for a newer fish finder. Last year, I was not impressed with my other two fish 10 year old finders in the deep water of Lake Michigan. I'm leery of putting holes in my transom though. Right now, I can get a bottom read at higher speeds. I would consider getting a poly plate to mount on the transom, so I could reposition the transducer if my first location isn't any better at higher speeds. Do these need to be drilled in or can they be glued on with confidence that won't fall off? There seems to be a million options with fish finders now days. I don't think that I need high end down imaging. I could maybe see side imaging working well on bago or Lake Michigan. Do you think that this option helps locate and catch more fish? Online reviews seem to favor Hummingbird customer service. I would likely, upgrade boats next year, so I would want something compatible with newer boat technology- ethernet. GPS is a must. I have a chip already for a handheld. Any other suggestions to help clear up all of the options? Any finders or transducers capable of seeing the thermocline since I don't have downriggers or temp devices for Lake Michigan? I may look at the smaller (cheaper) 500 or 700 series if they can do what I need on a smaller screen. $500-$750 would be ideal. TIA