Here is a review left by a customer on a product. Would you say he was satisfied or dissatisfied?
Title: Does not replace a good chalk line
Review: I have tried to use this tool on several surfaces - roof shingles, plywood sheets etc, and have not found it to work well.It is too delicate and only seems to work on perfectly flat surfaces. Not recommended. Give me a good old chalk line anytime. I'm sorry I bought it.
