Have had my T for the past few weeks and just returned from a 10 day trip to Fiji testing out the camera. My initial thoughts are:
Dials are pretty stiff. Hopefully they'll loosen up a bit with use, but the aperture ring doesn't move as smoothly as I would like (always compare this to my Leica lenses). Manual focus ring doesn't seem to move as quickly from closest to furthest distance either (I know this changes depending on how fast you turn it). Will likely just take time getting used to it, but as others have said in the past, I would have preferred a mechanical focus ring and not focus by wire. Although, oddly enough, the on/off switch keeps going on inside my bag. While I've heard others complain about this for years I've never had it happen with the original x100 or x100s. When going to review images I found all these black screens. At first I thought it was a corrupt card, but it turned out to be my camera being turned on and snapping shots in my bag. I also find the rear scroll wheel (used to be the jog dial) annoying as it is too easily hit and keeps adjusting my settings. May have to invest in a thumb grip to help avoid hitting the wheel by accident.
New EVF is really nice! I've never used it all that often in the past, but testing it and the new mini EVF out I actually forgot I was in live view for a moment! Out on beaches in Fiji I was actually surprised at how often I used the EVF over the OVF. New four way control buttons on the rear have great feedback (unlike the X-T1) and you can use the rear dial at the top to scroll through menus/images quickly just like you used to be able to do with the old control dial. Going to take some time to get used to the new button layout, but I do really like the ability to customize just about everything. This includes a one-press Macro mode which is SO much simpler/easier to use. Multiple customizable buttons and menu are two things, but I really like how you can have 7 custom pre-sets. Only shame is not being able to rename them! Would like to be able to do this on a future firmware upgrade.
Battery meter is accurate!! Well, more accurate at least. No longer do you go from full to empty in a matter of 10 shots. 3 bars, 2 bars, 1 bar, then red. It was a pleasant surprise as I've been accustomed to changing batteries without much notice.
At the end of the day I really only upgraded for one reason; wi-fi. I have an Instax printer and being able to transfer images directly to the printer (rather an an eye-fi card or downloading images to a computer) makes this a no brainer. Same goes for the ability to transfer images directly to my phone for sharing on social media. Being able to use the Fuji app to trigger the shutter is the other reason wi-fi was a big deal to me. This will make things much easier when doing long exposures rather than carrying around a shutter release cable and having to take off (and potentially lose) my soft release. I do hope Fuji updates the app to allow you to trigger Bulb as the 30 second max exposure doesn't make any sense to me.
Other than that, I feel it's a pretty minor upgrade and were it not for the wi-fi I would have likely stuck with the 'S'. The new EVF and rear screen are nice, but not nice enough to justify the 'T' over the 'S'. And for me, personally, I prefer the look over the x100/s. Even though the differences are minor, the new top plate lost all definition (in the grip, around the OVF, dials, mic, etc) and just doesn't look as nice as the older versions to me.
Apparently you could do this with previous gen x100 cameras as well. I've never tried, but others were reporting that it's possible, just wasn't advertised. That said, while it's a nice feature to have, it would be nice if there were ANY sort of indication that the battery was actually charging in-camera or a percentage of charge (think cell phone, laptop, anything else that requires a battery to be charged!).
The T also has the ability to charge the battery in camera via USB cable
A nice option that allows for charging 2 batteries at once