I am in the process of switching to a micro 4/3rds system and I am considering a sling style backpack to hold and carry my gear. I am a huge fan of LowePro as every time I have needed a bag for my previous gear over the years, I have always found that Lowe Pro has served me well. So I while I am leaning in that direction, I would like to hear other suggestions, particularly if those who have had experience with LowePro and others. My question is what size suggestions folks may have, I want to keep it as small as possible to accommodate my gear. I now have an Olympus OM-D E-M1 and will expect to have 5, maybe 6 prime lenses when all is said and done. One of the 5-6 lenses I am likely to purchase is the Olympus 300mm telephoto. Thank you.