You really feel passionately about this, so I'm hesitant to draw this out any further, but since I took the time to read your linked blog post I'm going to give you my thoughts anyway.
It seems to me the reason, if any, that RF focusing may be more accurate than live view on the M 240 as indicated in the blog you linked to is only because magnified live view on the M 240 is only in the center area and the area of magnification can not be moved around like on many other cameras with an EVF. So rather than see this as a shortfall of focusing with EVF's in general, I see this as merely a knock on Leica's implementation of live view on the M 240. If you could place the area of magnified live view on the spot in your image where you wanted the center of focus, I have no doubt that magnified live view would be as accurate or more accurate than the range finder mechanism.
The question is whether you believe focus is more accurate with RF (focusing in the middle). You can then knock on Leica implementation to argue missing functionality for not being able to move focus, but this is sidestepping the discussion on whether RF is more accurate than EVF (for wides -> short tele).
Its quite easy to test for yourself. I have done this in real life photography. *For me* the RF always beats the EVFs I have tried in terms of placing the focus plane where I want it by MF. And particular for situations where you have limited time to respond. Even for tripod work I prefer the RF, but the difference is less here since I have more time to endlessly adjust MF by EVF. I first experienced this when I was testing the performance of some of my Leica M lenses on my mirror less. I was really surprised how much easier it was to achieve accurate focus by RF.
But this is of course somewhat depending on persons, so please let me know your experiences comparing focus by RF to EVF (side by side).
Btw: I wish those answering could state if they actually have tried using both EVF and OVF, and for this part of the discussion RF OVF
. For the record, I have not used the Fuji X-s nor the M(240), but owned and used the GH-2, NEX-5n / 7, D700, RD-1 and M9. I should also say that I dont use longer lenses than 135mm.
Here is anther piece of information, using Leica lenses on the X-E1 (if you read further down you will a see a balanced conclusion).
"Putting Things in Focus
This is the crux of the matter: how to tell when you are in focus? With a Leica M camera you simply align the split image in the viewfinder and trust to luck that the system is accurately adjusted. It works well most of the time and is unlikely to give problems, especially with 50mm and wider lenses. It is possible to achieve accurate focus very quickly and some Leica fans reckon they can beat an autofocus lens any time. In many ways it is still the ideal way of setting focus manually, despite all the technical advances we have seen in the past twenty years.
After the week with the X-E1 and the Leica lenses I returned to the M9 to do some comparison shots and immediately felt back at home with the split-image rangefinder. If I am honest, it is a tad quicker to find focus than with Fujifilm’s EVF. The Fujifilm, though, is satisfying and accurate; it just goes about things in a different way.
Read more: http://www.the.me/using-the-fujifilm-x-e1-with-leica-lenses-a-massive-dose-of-m-magic-at-a-fraction-of-the-price/#ixzz2XJtW0HxD