I agree you should go by your instinct when you visit.
The school where I am governor was RI for a while and this was based on the SATs results - everything else was outstanding, but they have to put the school in RI if the prescribed SATs results are not reached - at that time we had 35% SEN in the top year and the children were making brilliant progress ( and were happy!), but not what the government dictates. Added to that the cohorts were tiny (6 - 8 pupils) and not statistically valid - but what the heck, the government cares not one whit about that.
So, as you can see, some of the decision is dictated from above and makes little sense.
BUT - big but - if the issues were around not dealing properly with bullying, then that would ring alarm bells with me. I think you need to go through that OfSted report and look at all the things that really matter to you that the school was unsuccessful at and go in with your bits of paper and say - OK what have you done about that? Do your homework!
Our little school got its GOOD this year; but again it would have been outstanding (every category was) had it not been for the high SEN in the cohort.
It is a lovely happy school that people are falling over themselves to get into; and the parents said they did not give a flier what the OfSted said, they knew it was great!
I think you are better of trusting your own instincts as parents and your knowledge of your children rather than some faceless official who pops in for a day, makes a pronouncement and buggers off over the horizon!