I believe it's a personal preference. As in everything, there are positive and negative to each option, Forced air can be considered "less clean" or more work as you need to change the filters. Many people with allergies tend to stay away from forced are systems, but the upside is Central Air. If the house does not have it, it's much easier to put it in as you can use the same air ducts. Bottom line, it''s most of the time not a factor in the decision making process. Fuel preference is also just that, preference. Yes, many people don't want electric, but with huge oil prices and education that electric is zoned so you can shut off areas of your home, Electric homes are no longer the taboo they used to be. Gas is preferred by cooks but some are concerned about the dangers of the home exploding. This also need to be addressed by consumer education. Well, I can go on, but you get the picture.