GL...
To be correct, you never take-off the A320 with Flaps 1 - that is a landing / approach setting. You usually take off with Flaps 1+F - an altogether different configuration!
We (BA) take-off usually using 1+F (but not always - e.g. ABZ) if we use the on-board Perf Manual. If we use the computer link then it gets us to use 1+F,2 or 3. It seems to have no rhyme or reason as to which, but then the speeds seem pretty random too! Whatever, I just fly the thing, and whatever random numbers it gives seem to work....
NoD