One of the advantages always taunted by pro-micro 4/3 users is how small and light their gear is. While this is very true, especially when comparing micro 4/3 equipment to regular dSLR equipment - and doubly true if one is using a full-frame dSLR! I mentioned in my post on using my Olympus OM-D E-M10 to shoot an event this past weekend (http://www.infotor.com/blog/om-d-e-m10-as-my-event-camera/) that my Lowepro Streamline Sling bag packed with my E-M10 and some other equipment weighed in at only 8 lbs. (3.6 K) compared to my Tamrac bag with my Canon gear at 14 lbs. (6.4 K).
As I thought about what was in that bag, I realized that I had two older Canon lenses in a small Eagle Creek utility bag included in the bag. Today I took this little bag out and weighed it. 2 pounds (0.9 K)! So, by replacing those two little lenses (a 35mm, f/2 and a 50mm, f/1.8) with MFT lenses, I could very likely reduce the total bag weight by a pound or so!
Moral: really consider what you are carrying and whether you really need it! I am very much, unfortunately, a just in case kind of guy. I like to have my bases covered, so I will probably always put more in my bags than I actually need!