Gurcem Eugene Zekai

I came from a 5Dmk2 and traded it in for my Fuji gear. I got an X-T1, grip, 18-55, 23mm f/1.4, and a 35mm f/1.4 right off the bat.
 
The X-T1 wasn't really a solid choice. It was good enough for most things, but still felt like a lot of a compromise in order to get a lot less size and weight.
 
I've traded my way up to the X-T2 and I'm much happier. I've also gotten rid of the 35mm f/1.4 in favor of the f/2 for focus speed, and gotten the 50-140. 
 
I was missing a really fast lens for dreamy bokeh, so rather than shelling out for the 56mm, I got a Mitakon 35mm f/.95 which I've been using for those sorts of portraits, and I'm really happy now. 
 
The 90 and the 56 are both excellent lenses, though they're both super specialized. If you shoot portraits a lot, then really you're going to want either the 56, 90, or 50-140. I haven't ever been let down by my 50-140, so that's my suggestion. The 56 focuses too slowly for me, and the 90 is just a bit too inflexible for my style of shooting. 
 
I also got the 16mm and really liked it, but I only ever used it for test shots here and there, and never found myself using it in real life. I never took a "real" photo with it, and sold it a few months after buying it. I get by with my kit lens being my widest.
 
"How good is the X system actually"
 
It's really good, once you bend your workflow to accommodate a bit of the quirks. The flash system is lacking still, but using Canon triggers for studio strobes works just fine. For portrait work in general, I'm really pleased with it, especially after the most recent update to the X-T2 which gave some welcome upgrades to workflow. The only times I've been tempted to switch back to a different system have been in terms of processing large amounts of photos. RAF files are slow to work with, even on fast machines, and getting fine detail AND color AND full latitude out of the files can be an arduous task. Recently Iridient came out with "X-Transformer" which you can use as a plugin in Lightroom which has really helped a LOT though, so things are getting easier and easier every day.
 
I can confidently say that my best photos I've ever taken have been on a Fuji, and it's going to take a LOT to get me to change to anything else again.