Thank you for the compliment!
The title is a bit misleading... The thread is in the Micro 4/3rds Cameras section and the content of the first post refers only to the GH4. Only the title said something about the Leica T.
I had/have several APS-C cameras and did a lot of shooting with them. I've never been fond of the 2:3 proportion however, even in 35mm film my favorite print was an 11x14 (almost perfect 3:4 proportion). Cropped to 3:4 on the typical APS-C sensor, you're shooting with a 16x21.3 mm sensor, which isn't that much bigger than 13x17.3 mm. You lose less from FT format going to my other preference square (1/4 vs 1/3 of the format area).
I believe the reason Leica chose APS-C was due to available sensors from Sony, and the fact that their camera's traditional format has been 2:3 since the 1920s. It does keep lens and body size down nicely, but not as nicely as FourThirds allows since the format diagonal is so much longer.
Given the enormous diameter of the lens mount AND the overall size of the body, I would not be too surprised to see a T model at some point in the future with a full 35mm sized sensor. Handling one at the shop on Sunday, it's not a small camera ... it's not so much different in size from the M type 240, really.
But back to the GH4. They had one on the shelf on Sunday so I was moved to look at it. Reminds me more than anything else of the Leica R8 based on the shape, but much more petite and light-weight.
G
I agree with your statements on useable sensor size from APSC if you crop down to 4:3 - then the size advantage is almost gone. But as I prefer either 3:2 or square I would need to crop on 43 down to 3:2, which even further reduces useable sensor size. My preference for 3:2 comes maybe from my decades long background shooting film cameras (yes I am that old - had my first DSLR a Minolta SRT101 back in 1967 if I remember right). The other format preference is square, which comes from my time with Hasselblad V system - one of the most exciting camera systems I ever used. Reminds me that I should actually get another 503C for a cheap price
Anyway mainly I prefer 3:2 and was never really happy with 43. But I have to agree that 43/m43 in combination with sensor size gives most of the times a real size advantage (most of the time).
I have the same feeling as you do that the Leica T could easily hold a FF sensor. And I would really welcome a FF Leica T solution with FF AF lens lineup. Finally the AF R system
But given the slow and long development cycles with Leica I have the fear this will not happen in the foreseeable future (speak next 3-5 years).
Coming back to the GH4 - I need to handle one, but from what I can tell reading reviews this camera indeed comes close to the old Leica R camera ecosystem - even a bit smaller. And offering such advanced video capabilities (4k) is for sure a big plus. Also keep in mind I really loved (love) the EM1, I just had to make a decision to minimize my investment for different systems and finally the XT1 won after considering all what is very important for me - obviously different things than for you.
But I might even go back into m43 once the Oly Pro system is really complete with Pro lenses - and I am hoping here for more than just the 7-14 and 40-150, but rather some 70-300 with at least constant aperture 4 etc. or an organic sensor with all its advantages, speak higher dynamic range paired with higher resolution so cropping to any format would no longer be a concern.
Meanwhile the Fuji X system will be my preferred solution - but never say never again
Times are really exciting!