Survey tools are great! But you are absolutely correct, you have to design them with an extremely scientific approach.
I will say… for me… All the survey data in the world isn’t going to mean as much as data gathered from face-to-face interactions with real potential customers.
I think surveys are the most powerful when you already have an active customer base to work from. They can help fine tune your product to meet the needs and solve the problems your customers are facing. @Dan and the Glowforge team did a great job with their survey’s in this respect.