I'm not the right person to ask for lightweight, my usual kit is in the realm of 5ish kg in total with tripod and with lenses. I borrowed a mate's Olympus OM-D E-M5 and paired it with a Panasonic Leica D 14-150mm F3.5-5.6 (equiv. 28-300) and found myself wishing for my regular kit. It's heavy but I don't carry all of it at once, I grab the lens that I'll be using that day and leave the other in the hotel room or in the car most of the time. Carrying a 5D3 with the Canon 24-70 f2.8L isn't that bad.