I agree with that. It is very hard to get hard evidence what works and what not. If it works, which i hope, i will add to the hardware base.
Today i got the printer.
Works very well.
First deleted the old drivers and installed the new drivers. After a test page i can say it works within Suse.
There are 3 option in the settings regarding duplex. And yes, it does suck the page in again to print on the other side. Very convenient. 
I will add the printer to our data base. Hope i am capable of doing this right.
Just to add a comment.
Yast (via GUI) did not allow me to change some settings. I overcame this in logging in the terminal as root and calling yast. This option worked for me. My first test was in Kmail and it worked. But it did not save my selection.
So just in case, someone else tried it and wonders why i did not work. Or perhaps its just on my pc.