Originally Posted by backpacker3
The only differance I can see from the 3M Brand is the price.
I wouldn't be too sure about that. 3M products are engineered with specific characteristics for specific purposes while outdoor Duck Tape is a generic product. The tape itself being water proof does not mean the adhesive is as long lasting nor that tape material is as durable to abrasion or sunlight. Both of these are significant factors in the performance of the material for the specific purpose.
Please note I haven't personally compared the two nor claim that 3M is the only sound way to solve a particular problem. Only that my experience with buying and using 3M products, particularly thier commercial and industrial products, is that they are well made and well used for the intended purpose. They get those high prices from commercial custoemers by being a high performance product.