I am considering buying one of these 2 and would like your opinions about them. The Desert Spring costs $259.95 plus 14.95 S&H and covers up to 4200sq ft. I think the Aprilaire covers about the same. It costs about 229.95 plus S&H. One thing that interests me about the Desert Spring is that there is nothing to periodically replace in it, just clean out a lower pan on it or install an automatic flush device on it. They say you don't need one if you have soft water. I would appreciate your opinions. Thanks