Yes ... but if you mainly photograph stills, or slow moving subjects, would the new features of the X-T2 really make a difference? I don't think my photography would improve even a bit if I would upgrade to the X-T2.
Hmpf. Let's take a look at that as I can't agree with much of what is in this post.
It is very sharp across the frame. It used to be my second sharpest lens after the Zeiss Touit 50mm f/2.8. Mine is about as good across the frame as the XF23 f/1.4, only beaten clearly by the XF90 and the Zeiss. Other lenses might be better at a certain aperture or certain characteristic but as an average of apertures from f/2.8 to f/8 the 27 is one of the best lenses I have tested from the Fuji line up. It does drop of significantly from f/11 on though.
It has a light barrel distortion which is well corrected in software, either in camera or Lightroom and also some coma but both aren't really problematic.
There seems to be some significant spread between various XF27 lenses, I tested two of them and both were very close together, but there are other results on the net to be found which show weak edge performance which I can't reproduce with the lens I have here. So be aware and test the one you receive.
XF35 f/1.4 and f/2
Between these two lenses there are reviews that show one or the other being stronger optically, I own both and can say that without a doubt the old f/1.4 beats the new f/2 lens easily in optical performance from f/4 on. Contrast, micro-contrast, center resolution, resolution across the frame, distortion are better on my f/1.4 than they are on my f/2. I have seen tests stating otherwise even though when looking closely at their examples, it shows that they actually get same results as myself.
The f/2 is clearly a newer lens from Fuji, more solid barrel design, faster AF motor, nearly completely silent operation, tight aperture ring and the WR badge show this fairly clearly. Optically, the XF35 f/2 beats the old f/1.4 only at it's own wide open aperture and only in the wide corner area (not really close to the corner where the f/2 falls off pretty badly), which is kind of surprising – at f/2 the new lens shows more contrast in all parts of the except the center.
The new XF35 f/2 is unfortunately absolutely terrible in terms of optical distortion correction. The barrel distortion is extreme.
For landscapes between my two copies of the XF35 lenses the f/1.4 is better as it recovers much better over the whole frame from f/2.8 on where the two are comparable but from f/4 on the old lens shows clearly more details and more micro-contrast across the frame.
Regarding AF performance, the new lens IS slightly better, but only slightly. The old lens makes a lot more "fuss" about focussing with a noisy motor and some squeaks here and there though making it "sound" slower.
You also have to be REALLY careful when looking at reviews of the lenses as all Fuji lenses seem to have variations between individual samples. So, you might get a really good XF35 f/2 or a really bad XF27 and your results can vary.
Also, one more word of caution with regard to reviews: some reviews use dcraw to develop the raw which used to be absolutely terrible in de-mosaicing x-trans files which means the resulting resolution graphs were really bad for the simple reason that the software was crap and not the lens.
Conclusion from above
If you are looking for best optical performance, the surprise here is that if you get a good copy of the XF27 it is optically better on average over the respective full range of apertures of each lens than either of the XF35 lenses.
Now, that needs to be qualified though because if you take all three lenses and compare them from f/2.8 to f/8 only, the optically best I have here (and have tested personally) is the XF35 f/1.4.
No matter though, if it is really the only lens used for a while then I would HIGHLY recommend the XF35 f/1.4 for the following reasons:
It recovers optically better from f/2.8 on than the newer f/2 lens.
It delivers one stop more light which results in more creative options shooting wide open as well as more exposure options shooting in dark areas AND it lets in twice (compared to f/2) or even four times (compared to f/2.8) as much light onto an auto focus system so can be more precise.
It is optically better corrected than the two other lenses.
The XF27 does not have an aperture ring which I personally find a downside but others might disagree here.
While f/2.8 is not really slow, it is two stops slower than f/1.4 with all the creative disadvantages and exposure downsides.
The field of few is actually quite a bit different between the 27 and the 35s.
If the only viable financial option is between XF35 f/2 and the XF27 I'd go with the one that is closer to the preferred focal length.
Waiting for 23 f/2?
Why on earth would someone wait for a lens that isn't even on the Fujifilm lens roadmap yet? The rumors stem from an interview where a Fuji executive said that "people have asked for more compact slightly slower lenses" and that they'll likely develop some of them. Really, you're going to wait because of a rumor?
XF27 vs. any of the XF35s
I have not used the XF27 much in the last year since I bought the XF23. I basically pack it in my bag when I take the X-T1 on a longer trip to have an option to remove the ArcaSwiss plate from the camera, mount the XF27 and have a very compact system. But mostly I just take a bag with me and pack the 14, maybe the 23, definitely a 35 and maybe if I'm after portraits the 56 or 90.
The XF27 is an okay "only lens" for me, but the XF23 and either of the XF35s are better "only lenses". I'm more a 35 than a 23 fan, but that's personal.
The 18-55 and 16-55 are optically the best. They are optically indistingishable from the primes, except for the maximum and minimum apertures. The 18-55 is also fairly light. If you want a zoom simply so you don't have to switch lenses as often, those are the lenses to go for.
The 10-24 is alright. It gives you focal length options you don't have and it's optically good. If you simply want to expand your wide-angle options, though, the 14mm and 16mm are both a little sharper and faster. 10-24 isn't really a focal length that is going to adequately replace your primes. This is the lens to get if you want to add to your existing primes as a full kit, it's not a lens to get if you want to leave your primes at home.
The 18-135 is optically the weakest, and for most of its focal length it is the slowest lens. It's also comparatively large and heavy. If you want to expand your focal length options and you want to have just one lens on your camera and never change, this is the one to get. You're swapping quality for convenience.
There's no right option here. All depends on why you want a zoom and what you expect to get out of it compared to your primes.
As for colour, I'm of the mind that every Fuji looks better in silver. The silver X-T1 is also slightly, slightly more weather-resistant and tougher than the black version. Just bear in mind with the X-T1 that silver comes with an additional cost.