One early change was the DFB deciding to expel last year's finalist DFC Prague. The DFB had originally admitted "German and Bohemian" based clubs in Czech areas of Austro-Hungary. This was partially because the DFB felt that these clubs were discriminated against by Czech authorities. Not only did they admit these clubs into their own federation, but they banned German clubs from playing friendlies against Czech teams, such as the famous Slavia Prague. However, by joining FIFA, the DFB was now only permitted to admit clubs from Germany - so DFC Prague had to go. (DFC went back to Bohemia, and then was part of Czechoslovakia in 1919. They competed in the top Czech league in the 1930s. The Nazis then banned the club in 1939, as most of the members were German speaking Jews.)
Once again, Karlsruher FV was at the center of the contraversy. Apparently many of their best players were unable to get time off from work to travel to Berlin for the quarterfinals. So basically, their "B" squad got their ass kicked by Britannia. (BTW, the referee of the match was none other than Franz Behr, now 2nd chair of the DFB). However, some KFV officials discovered that DFB regulations apparently indicated that matches should be carried out on neutral ground. And of course, the match with Berlin was on Britannia's own field. So KFV lodged another protest. When the DFB finally got around to ruling, the final was already set in Kassel, with defending champ VfB Leipzig to face off against Britannia. Interestingly enough, the DFB decided that KFV's protest was legit, but the action taken was rather drastic: the whole championship was canceled.
The competition, as it played out, was actually quite interesting. Defending champ Leipzig had a tough matchup against regional rival Magedeburg, and required 132 minutes (no penalty shootouts) to prevail over Duisburger SV. Aside from their easy pounding of Karlsruhe, Britannia put in an impressive away win at Hamburg, where they were considered a slight underdog. Hamburg had overwhelmed Hannover in the Qtr-finals, and the Hamburg league was considered quite good. Hannover on the other hand eventually gave up football and switched to being just a rowing clubs.
The western champion was Duisburger SV, who were once a power, but eventually disappeared from sight. You can read more details on them in the Essays section.
Qtr finals: Germania Hamburg - ARBV Hannover 11:0 (8:0) Britannia Berlin - Karlsruher FV 6:1 (2:1) Duisburger SV - Casseler FV 1895 5:3 VfB Leipzig - Viktoria Magdeburg 1:0 (0:0) Semi-finals: Germania Hamburg - Britannia Berlin 1:3 (0:3) VfB Leipzig - Duisburger SV 3:2 (0:1, 2:2 ot) Final: (Kassel) VfB Leipzig - Britannia Berlin canceled