I suspect that I'm in the same camp as the OP.
Looking for justification is often part of the process. But, owning two bikes that you want to do the same thing is the hurdle; at least it is for me. And then there are issues about garage space. But most importantly, it's about dividing your time and interest between different bikes. Most of us understand that really getting to know one bike can be a challenge. Getting to know two bikes well is twice the challenge. I've never found a bike to replace my FJR. But I keep giving those Gixxers a sideways glance and wondering, what if...
I was doing the same thing (only a CBR instead of a GSXR). I got the F4i in may, and as the summer went on, I found myself riding the FJR less and less. After my trip to MI on the F4i in July (thanks mostly to a leaking fork seal on the FJR that I couldn't get the parts for in time for the trip) I quickly reached the point where I was only riding the FJR when I was riding with my Dad (which meant I wanted the CB so I could talk to him).
If I figure out how to mount my J&M on the F4i...
