A couple of decades ago when I actually worked as a professional portrait photographer behind a Mamiya RB67, in the 35mm field where the Nikon F series dominated as a press/reportage camera, the M & R series Leicas had a serious reputation for superb lens, coupled with amazing build quality of both lenses and body, that in turn was backed up by what one could see in terms of output using slides, by relatively easy side by side comparison.
I'm not a professional photographer anymore, merely a semi-serious amateur, and I still shoot with a now very elderly Olympus 35mm film rangefinder camera. And for digital, my iPhone 5s *cough*...
I've long hankered after a digital SLR, but the lack of FF sensors (until fairly recently) and weight and bulk put me off the concept.
But then the game changing Sony A7r arrived - FF sensor in a very compact body, and some very choice Zeiss lenses available.
And Leica have come out with the X2 and X Vario - a 'slow' and fixed, but very high quality zoom lens on the Vario, where again, on the basis of what I've seen re files, I personally prefer the 'look' of the Leica lens on the Vario, over the Zeiss's of the Sony, despite the lack of flexibility that the X Vario suffers re it's fixed zoom lenses in comparison with the I/C lens A7r Sony, and despite being 'only' an APS-C sensor.
But there are occasions when I might like a long telephoto, or a wide angle, and that lack of versatility is what holds me back from pursuing the XV Leica.
Along comes the new T - with the 'new' zoom for it, one more or less has an X Vario - but with the ability to change to a telephoto or wide angle if needed.
For build quality, I think it will be out on it's own, barring perhaps the M 240, or something like a Hassleblad, or an S2 etc.
From the files I've seen, the quality is there, as is the Leica 'look', and even some quite reasonable 'bokeh' despite being only an APS-C sensor, - which is where the X Vario with a slow aperture + APS-C sensor does not do so well IMV.
No, short of the expense of an M, I think this is likely to be a superb camera to be honest.
And IMHO, there is an awful lot to be said for quality, elegance, and simplicity of operation (less is more) or concentrating on the essentials as Leica put it.
I certainly found handling the Sony A7r not so much as daunting, or confusing, but just needlessly complex, in that unless using it everyday, one is going to be referring very frequently to the instruction manual to make best use of it.
And most modern, DSLR's are similar, in that they are very much the amalgam of computer and camera, which from an intuitive, creative tool POV, mitigates against them IMHO.
Naturally, I would want the EVF, as holding a camera out in front of one at arms length looks terminally silly IMHO, and likely to lead to camera shake; much better to triangulate with elbows against chest, and hands locked around the camera braced against forehead which the EVF (with diopter adjustment) will naturally allow.
Or for some situations, perhaps use a tripod.
With an iPhone, - offering iPhone screen display of what you see on the camera, as well as being a remote control for the Leica T - very, very neat idea indeed, for which I can see quite a lot of use.
As is the WiFi file transfer to computer, or social media, and GPS info etc.
Clearly, on design, build and features, this is very much a Leica for the 21st century, whilst simultaneously embracing all that history has proven a Leica to be as a creative and superb quality photographic tool, over the many decades they have been making optical instruments and cameras of the highest quality in Wetzlar.
Best
John..