If there is one thing I recommend to people before they make a major treadmill purchase, it is to read the reviews. There is simply no shortage of firsthand reports available on the web, so please avail yourself of them; this will definitely pay off. You will save more than enough money and heartache to compensate you for the time it takes. There are many good sources of treadmill reviews on the Internet.
Some are obvious and some are hidden. You always have to watch out for undercover agents of the various companies involved though. These are pretty easy to spot if you have an eye for them. They will go something like this: "OMG this treadmill is like Heaven. I lost 25 lbs. in my first day of owning it." Well, maybe that is a little exaggeration but you get the point.
For me, the purpose of treadmill reviews is not just to give an evaluation of the product, but to let me know what is important to look for and what is not. I mean, looking at pure specs and numbers can be such a turn-off. I don't even know what I'm reading! 25 mHz what? 2.8 horsepower motor...
These things don't mean anything to me. I want to know what this treadmill is going to do for me - a person. How does it feel to run on? Can I plug my iPod into it? Did it hold up well after a couple years of running on it? These are the things that matter to the average consumer; not a bunch of numbers and engineering type statistics. (Not that there isn't a place for that but...)
I really like when people have had experience with a number of different treadmills and they have been around the industry for a long time. In this world that means something like ten years, seeing as the machines were invented not so long ago. People like this, when you read their treadmill reviews, can provide a whole lot of value. They can tell you if a certain model is a good value at its price. Maybe it would make more sense to spend an extra $100 to go with one that will actually way outperform and outlast the other treadmill..
In the end, it's all about just being a smart consumer. Any purchase that costs a bit of money is worthy of some beforehand research in my opinion, and this is why treadmill reviews are so valuable. You are probably going to end up spending anywhere from $500 to $2,000, so it is in everyone's best interests to be diligent.