Completed German tree! Wunderbar!
I started the German tree about four months ago but I didn't practice at all until about three weeks ago. I cracked down and just focused on German and got it done by practicing and completing skills for 6+ hours per day. Note that I studied German in the past and listened to a lot of German music, etc. so it wasn't as difficult for me. This is my second tree completed after Spanish and I'm almost through with French. Yay!
I can comfortably converse in basic German at least. Completing the tree builds a solid base but it will not make you fluent. Continued practice is key to help ingrain what you learn into long-term memory. It took me about 16 days of actual practice within a span of 3 weeks but I was at level 5 from when I started German about 4 months ago.