I have been through the appeal process this year, and did suceed but I can say its not a process I enjoyed - incrediably stressful for both parents and child.
We were doing it as they changed the rules last year, under the old system we would have got into our 1st pref school (where her older sister is) despite being out of catchment. New Equal Pref system meant anyone living nearer the school got it whether they put it 1st, 2nd or 3rd.
We had a number of reasons why we felt our daughter should go to that school, one of them being that she has no road sense. And to get to the school she had been allocated she would have to cross lots of roads. This has been already proved on the two days she has come home without her sister she has had difficulties, including managing to walk past a pedestrian crossing and then trying to cross and almost get run over at a set of lights with no pedestrian phase. Doesn't matter what I do she just seems to be in a day dream when near the road - dangerous combination. I'm just so glad that she normally has her sister with her.
At the appeal process they read out the comments of previous parents - about the size of class rooms etc, and the council's comments back. This freaked me slightly as my appeal was totally relating to my child rather than the physical building.
I would be careful about making up lies as they question you, and I wasn't quite prepared for that and was thrown slightly. Not that I had lied, just I prepared for the questions I was expecting, whereas the conversation developes and it would have been hard to cover lies. Though you could probably exaggerate some problem easier.
Places were annonced in March, and the appeal was in June, though we were able to ring up the day after to hear the results. I was an emotional wreck when I made that call, and asked her to repeat the fact she had suceeded in her appeal twice just to be sure I had heard correctly.
I was prepared to wait all the way to the 1st day of term even if we didn't suceed.