I had recently bought the Martha Stewart simple desk and fabric chair and realized it was too hard to move the chair in order to sit at the desk. I also didn't want the chair to push permanent holes into my carpet. I was afraid I'd stub my toe on the mat but it lays perfectly flat and hasn't given me a problem at all. I had expected to have to put $40 to $50 into such a mat but it was less than $20! You can't beat that value and even though it isn't the highest quality available it works perfectly fine!
Next purchase I would buy a bigger mat. Thought this would do the job. Got a deal on it deals are not always the best. Probably great for smal desk area.
This is the second chairmat I've purchased in the last two years. Just tossed the first one (same brand and quality level) due to severe cracking. Label says it's guaranteed but it's a pain to take it in and I couldn't find the receipt so I just got another one which I'll probably have to toss in two years.