i tried 0.74-2 and its still equally slow, its usually between 5~30 times slower than ntvdm depending on application, which is not remotely acceptable.
I wonder what type of non-game DOS application that you would consider it slow running on DOSBox with modern machines. On today Core i3/5/7 with over 3GHz, especially the desktop-class CPUs, DOSBox is extremely fast. And, on which version of Windows NTVDM that you run the same stuffs which is faster than DOSBox.
I would look from the user experience perspective of "fast" vs "slow", so please don't quote benchmark figures as comparison. For eg. if a game running on emulation would sustain 60FPS while getting 600FPS on native machine, then the extra 10x FPS is not really making any difference on user experience. DOS is a long dead platform commercially, so no new DOS games/application are being published with CPU/GPU heavy contents to make them relevant for modern machines. Hence, DOSBox is really good enough, with just a few exception of DOS games. I run the last version of AutoCAD DOS R13 on DOSBox and it was the fastest experience I ever had using AutoCAD.
No 64-bit version of Windows has ever shipped with NTVDM. It is obvious that 64-bit runtime is not suitable for legacy 16-bit real-mode, and if Microsoft were to support this they would have to do this in pure emulation similar to DOSBox. Both Intel/Microsoft has been keen on killing off DOS/16-bit real-mode for the last 20 years. The era of 64-bit computing has just made it even more compelling. Intel will put the final nails on the coffin by year 2020 when every new system will be at least UEFI class 3. And as I looked into the crystal ball, it painted the vision that Intel/AMD would completely remove 16-bit real-mode from CPU by 2030.