Edit - looks like the noise levels are different also.
Vivitek H1180HD - 2000 lumen 29db eco 33db std, life 6000 eco or 4500 std
Vivitek H1185HD - 2500 lumen 32db eco 35 db std, life 5000 eco or 5000 std
Infocus IN8606HD - 2500 lumens 29db eco 33 db std, life 6000 eco or 4500 std
Vivitek offering extra year warranty though, interesting. I must say that I tried the IN8606HD on std and the noise was real bad, made for deaf people imho, mine is staying on eco.
Looked in my Infocus IN8606HD box for evidence, not much in there but the label on the HDMI cable supplies further confirmation if needed of a common manufacturer, its labelled as a "Qumi" cable (as in Vivitek LED projector Qumi).
Looked again at the french site you linked to the onscreen menus of the 1180 unit are exactly like mine
They are subtly different models of the same unit, co-manufactured.
Very happy personally, with the IN8606HD, as a previous owner of an Optoma H27 and Infocus X10. Guess we need to await a professional review. As ever you need to tweak the brightness, contrast and saturation to suit your taste, initally I hiked up the brightness too much and then yes the blacks were poor then.
I have a Panasonic LCD TV next to it and if I have them both on, yes the blacks are deeper on the TV, thats only what you expect though, but there is a world of difference though versus the old X10, I really avoided ever comparing the TV and projector picture as the X10 was so dim in comparison it was unbearable - it really shows how far budget projectors have come in the last couple of years.
Its not like I had an extensive choiceanyway, I needed a unit to fit existing mounting and screen, a throw ratio of 2.07.