I too hesitated about the mounting method to use when I installed two 80 watt panels on my Bigfoot
last year. After much research and deliberation, I decided on the VHB tape. I used much larger Z brackets than were supplied with my panels. The Z brackets I used have a contact area of 2 x 4 inches vs. the 1 x 1 ½ inch supplied with panels. See attached pictures.
After one year and 4,000 miles, I have had no problems. The panels are very secure and feel like they would be difficult to remove. I will be at the Bigfoot Rally
this year where you could take a closer look if you are attending.
I still plan on writing a detailed procedure on my solar