Hi Greg, I have done Everest base camp. I have travelled a fair bit over the years and i have a strong philosphy - when travelling you are normally only there the one time (especially true with Everest base camp), so you need the gear to do the job and do it well. I carried my 1DMkII to base camp but if I had to do it over again I think I would buy myself a lighter DSLR just for that particular trip (40D, 5d etc). I did hook up the camera onto straps on my back pack but it was still quite cumbersome given you are continually climbing for 10 days, it did get heavy. In this area it is a real compromise between convenience and weight. One of the other guys I travelled with used a 40D and did shoot twice as much as I did - due to the fact eventually I had to put my camera in my back pack and only pull it out during stops (and then I did not every time). It is a tough climb to base camp but the scenery is breath taking. Best of luck with your travels.