What an excellent quick service. Ordered the focusing screen on Monday
3rd of October, it was shipped on Tuesday 4th, and receiced on Friday
7th (in the Netherlands).

Installing the screen was easy and takes only a minute or two. But I
would like to make a few remarks on the installation, as it is a bit
different from the description in the PDF manual for the 300D and 20D,
and the first time I had the screen rotated by 180 degrees by accident.

On my 350D there was one (not two) copper shim underneath the original
screen. I left that in place, as Haoda already mentioned.
To orient the screen correctly, you have to do the following: put the
matte side towards the viewfinder and the shiny part (difficult to see,
but you can see it when you look at the prism part) towards the mirror.
The two ears on the short sides of the Haoda screen must be oriented
towards the shutter (so they are the deepest inside the camera when
looking from the lensmount).

This last step was where I went wrong on the first try, because the two
ears on each short side of the original screen are nearest to the
lensmount. I figured that the Haoda screen had to be placed in the same
way, because I had not found a clear installation description for the
350D screen.
The result was that the screen was tilted a little, showing no accurate
focus when I used the auto focus on my 17-40L + 350D, which is spot-on.
After replacing the screen in the correct orientation, it proved that
everything worked as it should.

The only thing that is a minor disappointment (but I knew this in
advance) is that the red autofocus indicator lights inside the
viewfinder are no longer visible as spots. They now are a very fuzzy
blob of light. But if you really want to know in which position they
are set, you can look at the LCD on the back of the camera.

Perhaps it is worth a try to make some very small pinpoint holes in
the 'shiny' side of the screen at the location of the autofocus
indicators (look at the original screen were to make them), because
that's the way how the red dots show up in the original Canon screen.
The light is captured and scattered in the small hole, so you can see
it.

Best regards,

Matthias Meijer