I installed one this summer (this model http://www.optex.fr/Fiche.php?superfam=SUPF5&sousfam=C29B&ref=701260)
I set it up in the Lisieux region (14) to receive ASTRA.
After carefully considering my installation, I locked onto the satellite after just one small horizontal adjustment. The decoder indicated a quality of 90%.
The reception of the channels is very good. The antenna mounted on the facade is quite discreet. (That's relative: it still measures 60cm by 30cm.)
In short: I am thrilled with my purchase!
The only thing is, I forgot to bring a compass. I had to make do with a plumb line (well, a stone line would be more accurate) while watching the shadow at 2 PM... ;-)
Likewise: I didn't have either a protractor or a level. I managed with my plumb line and a bit of trigonometry.
In one afternoon, I installed my antenna, ran the cables, set up the decoder, and completed the finishing touches.
I was able to enjoy the inaugural ceremony of the Olympics with a crystal-clear picture.