I had my maxim installed in July. Started burning pellets on July 22. I will not use it to heat hot water in the summer again, unless I like really expensive unlimited hot water. My wife commented that she got spoiled by the amount of hot water available, which means I am not sure about that statement. I love it. I have been buying pellets by the ton for the most part. So far I have burned 6 and a half tons since mid July. Two tons were burned before Mid October,mostly for hot water and a little heat. Since then I have been heating the 2700 square foot house and a small workshop in my garage. Pellet usage I now about a ton every three weeks. There are a couple of caveats . One is that I have not found the best pellets yet. Two is that I had some work done on the house and the contractors were using the garage to do some work in. With my permission, they used the heater in the workshop to make the uninsulated garage comfortable. This really increased pellet usage.
I would definitely get the add on pellet hopper. I can put a ton of pellets in, and only have to pull ashes forward and throw some ashtrol in everyday. I do check it everyday, it is a wood burning furnace, but it is pretty easy to maintain. I clean it out once every three weeks or so. I would have purchased a owb if I was younger and had a woodlot available,but I am happy with the maxim.