Dear ganainm,I'm not in Germany but in nearby Belgium.
I can't really comment on the Guild as it is not a model I know. I'm sure someone here will have experience with it though.
Neither do I know where in Germany you are or your budget. If cost is a limiting factor I would suggest you could do far worse than a Seagull 12-string (made in Canada). The build is generally reliable and good quality, the action good and they now come equipped with a good LR Baggs pickup system which, in my opinion, is as good as the more common Fishman system.
Here is a link to a German site that carries the Seagull line so you can get an idea of price.
I play a German guitar myself (a Lakewood M-18 6-string, made in Giessen). This is a higher quality and more expensive instrument and they make several very good 12-string models. However, being in Germany, you may be able to find a good second-hand model by ring round some of the local stores.
Hope this helps a little.
mooman