I have been back and forward through this cycle over the years. I used the 5d2 for many years and supplimented it later as I wanted to downsize. I used exclusively Fuji cameras for about 5 years. Most of their offering from x100, xpro1 to XT1. I love the fuji cameras for their size and iq is great. The lenses are on the most part very nice too. However recently I have come back to canon and bought a 6D, which I absolutely love. Read all the arguments you like, but for me the FF character and images from the canon are just something I prefer. Its hard to quantify, but they are different and much of it is personal taste. For me, as much as I still ove the Fuji files, I prefer the canon files. The 6D is a great walk-around too and much more comfortable than my old 5d2. I have always preferred primes anyway, so when i want to go lightweight or am travelling i have a pair of very comapct MF voigtlander lenses - 28 and 40mm and sometimes i throw in my canon 50mm 1.4. The voigts are quite cheap, very solid, but very compact. I use a BlackRapid type sling and honestly, it is not much difference to carrying my XT1. I love the images i get from the voigtlander lenses, especially the 40mm. It hits the sweet spot for focal lengths for me and its chipped, so you get focus confirmation in the camera. You will save yourself a fortune going this route instead of investing in a whole new system, and u still have the versatility of FF and the use of the lenses you already have. Personally I would never trade my 6D now for my Fuji or any other smaller format system.