the point of edo tensei is that kabuto beleives other peoples power is his own. using those people like that ties in with his.....self deception...whatever itachi called it. and that was kabutos contribution to the war. and it made things interesting. i guess you didn't find it interesting though.
I found them interesting to start, but most of them had anticlimactic ends and the fights were short. Madara may survive but there's no reason he should right now, unless Kishi adds another explanation. Just because he's strong he doesn't make him immune to edo tensei, that's my opinion.
The point of Edo Tensei is to be able to bring back an unkillable army of the most powerful shinobi in history. Madara seems to have used this to its fullest effect by essentially dropping two planetoids on himself to take out the shinobi army.
The only issue with the way the resurrected shinobi are deployed are that they do not compliment eachother very well. This is further complicated by the fact that Kabuto was relying heavily on the inability of the Allied shinobi to effectively combat their loved ones. A better way of employing Edo Tensei would have been for Kabuto to resurrect the Allied shinobi as he killed them to increase the size of his army. Tobi and Zetsu could have continuously collected bodies (living and dead) for Kabuto to turn into Soldiers and the Edos on the battlefield could summon the new "recruits" into combat.
I found them interesting to start, but most of them had anticlimactic ends and the fights were short. Madara may survive but there's no reason he should right now, unless Kishi adds another explanation. Just because he's strong he doesn't make him immune to edo tensei, that's my opinion.