Rannoch was a pile of crap. The most important function the choices had for me wasn`t even to see the outcome of them. It was to develop my character and to shape his/her mentality and views. But it is useless if the writer declares one alternative as morally superior and lets your character look like an idiot for not following this one. If all you can do is to voice a strawman version of the position you want to take and the supporter of your position have the personality of fairy tale villains. That is what Rannoch was and I'm glad the ending apparently wasn't written by the same people who wrote this. Tuchanka also suffers from this problem, though not as much.
Edit: Besides, your choices in the Rannoch arc only mattered if you favoured peace. If you simple want to give the Quarians their homeworld back and get rid of the Geth, it doesn`t matter what you did before.