My German is beyond rusty, but yes, it works well if you have enough RAM. I did this a while back when I replaced my hard drive with a compact flash card. My motivation was to reduce writes to the flash memory. I have not done any testing to see how performance was affected, but it definitely did not hurt my system.
I did not impose that 128 MB limitation, it has given me problems in the past. Here is what I added to fstab:
tmpfs /tmp tmpfs rw,suid,dev,exec,auto,nouser,async,noatime 0 0