To the original question: yes, I am, but in a very peculiar sense. I tend to use one system, one camera or a group of similar cameras exclusively for a period of time and then change for whatever reason (equipment needs to be repaired, found a fault or can't find a particular accessory, etc.) to another camera or system. Unlike the OP, I can't just grab one and use it one day and the next use something else.
I have far too many cameras and I have a love/hate relationship with them. Six months ago I was using two Nikon F90X and really liked them. But, I wasn't happy with the height I was carrying, so started to look for solutions. First, I changed the lenses to ones less heavy, then I put aside the F90X in favour of the F80 and F75. I ended up looking at my Nikon EM and started to investigate it and its history. Fell in love with the EM and the Series E lenses. Now, they are the only ones I use.
It seems to me, I am never happy with the equipment I have and I'm always looking for faults or don't like the way X camera does one thing and keep changing cameras and lenses looking for something that is perceived to be better.
These days, I'm doing the opposite, looking at cameras that are perceived as lacking features and see what I can do to overcome their limitations.