Marko, I use RB and something simillar to F5, that is I use Canon EOS3. In previous times, when I carrying camera aroud and snapping on this and that, I used EOS3. Now, I bought Bessa R2A for carrying around, and almost all other photography I do with RB. RB is camera for slow work, that is setting a tripod, metering with handheld meter, and thinking whow and why you photographing that subject.
What I want to say, both cameras are good, but thing is in approach. There are different philosophical approch for using those cameras. Are you fast moving, automated photographer, or slow, contemplative, manual working photographer. Answer on that question is answer on question which of those cameras to get.
When I was younger fast moving photographer excited with automatization I used EOS3. With years I changed as person, became relaxed, and now my EOS3 is in bag using now and then (for example I plan trip to Jordan later this year, and I will carry EOS3, not RB, weight and space reasons), and my RB is in full use.
Whatever you decide, good luck.