I had my interview at the Dallas DO today May 14th. It went very well. I was very nervous about my extensive travel over the past 5 years. I had some 800 odd days of travel that included trips to a lot of countries in the world. But none of my trips was over 6 months, the maximum trip length was 110 days. I was working for a US company as a contractor and did have a letter from the company for the reason for the numerous visits.
If anyone's interested: I had an appointment today for H1B visa revalidation. Overall it was a smooth experience. I was asked for my paystubs though.
Degree etc was not asked for. Total interview time was 2 minutes. The only question I was asked was whether I am working for the same company for which I had received an H1 visa previously. In my case that holds true. I also had an F1 visa previously. US Degree.