REALLY. I use it on the D80 I shoot my Sigma 50-500 on... I end up carrying the "BigMa" around for six or seven hours at a time (generally with a D40 with a 18-55 around my neck as well) and the Op/Tech strap REALLY cuts down on the perceived weight. It is kind of "strechy", and the no slip surface keeps the 400 pound lens on my shoulder where it belongs. I am going to be ordering one for every DSLR I own in the near future, and I advise y'all to do the same. Highly recommended. It is available HERE: Clicky to buy an ubercool strap!