I sold a D700 with 24/35/50/85 setup for an X-E1 with the 18/35/60 setup. Even though the 35 was easily my most used lens, I'd convinced myself that the 28mm-e of the 18 would eliminate the need for both the 24 and the 35. And it turns out I do use the 28 way more (and more effectively) than I ever did the 24. But it also turns out I need a 35mm-e lens. I'll bring just the X-E1 and a single lens to dinner/parties my wife and I go to, and I've now taken both the 18 and the 35 (on separate occasions) to a few spots and found them to be too wide or long respectively for the shot I want. So I knew I needed a 23mm solution.
I went for the X100s. I got mine used for $1000, and it is like new. Great deal, really. I like that it adds a second body and that they effectively have the same sensor and image quality. I now can see a few different uses for my gear.
1.) Just bring the X100s, for moments where I want to travel very light
2.) Just bring the X-E1 and one lens, probably the 35, if I know that one lens will work (an outdoor gathering, for example)
3.) Bring the X100s and the X-E1 with the 60mm and nothing more. Great pairing, no lens changes.
4.) Bring the whole kit, for a specific goal or for travel.
I like having all of these options. For me, the X100s (in like-new condition) for $1000 just killed the idea of getting a 23mm lens that's a stop faster, much bigger than my other lenses, doesn't have an extra camera body attached, and would need a newer body (X-E2) in order to be as fast as the X100s, all for only $100 less than the X100s cost me.
As it stands, my first upgrade priority will be that X-E2/X-Pro2. After that, the 14, 56, and 55-200 all seem possible. I'd take a 90mm/2.0 if they made it. And I'd upgrade my 18 or 35 if they reissued them with the manual scale focus clutch found on the 14, 23, and 56. But none of these things are priorities (except a body with PDAF pixels). I could reasonably see myself not buying another lens for years.
...but typing that just now feels like absolute folly...
Will