I am a newbe here but I just have to make a comment. Why the Marcum Challenge?? The Challange to me appeared pointless. If you want to sell and promote a product, just take it out on the ice and show it off and it will sell itself. But If the Marcum product is so great, why do you have to have a challange?? If the product is so good, let it stand on its own to feet. I feel this is a very bias evaluation, in my eyes. I have not yet had the pleasure of using any of the Hummingbird units but I felt this article was meant as a straight forward attack on one product. I have used Marcum for years and switched to a FL18 last year after getting sick of interference problems with everyone I fish with. Yes you can reject it out but it is a pain to do every time you go fishing with people. Everyone I fish with runs fl18’s and we have no interference issues what so ever. As for the Marcum, of the 8 or so years that I used Marcum products, I had problems three times, each and every time, the customer service from Marcum was second to non. To sum up my comments, one thing a person may want to consider is what types of units he or she may be fishing by on a regular basis, it can really make things much simpler.