Ok, as expected I get a very nice global picture here, from all comments so far

The EmpegBBS never disappoints.

- "Braced" shooting position is a very relevant advantage of the vf (both optical and lcd) over lcd-screen.
- These are, however, the issues caused by the LCD technology per se, both on a display and in a vf:
LCDs on cameras are all currently extremely low resolution, have poor colour reproduction and contrast. Oh, and they're slow.
[...]
The prism and mirror also mean you can use a dedicated auto focus system that doesn't need to use the image sensor. Which means faster and more accurate focusing.
- And finally, in favor of an LCD display:
I appreciate a good LCD and a swivel allows all manner of shooting when you can't put your head behind the camera body.
In fact, as to my little personal experience, so far, with my reflex, I think I would in the future upgrade it for only two reasons (leaving all the rest unchanged), one of which is a swivel LCD.
The other being a Full Frame sensor.
Both reasons are not at all primarily important for me at the moment, but, in pure theory, I would not mind adding those features to the ones I have.