correct, the latest firmware is 2703 for the Z700, and 2503 for the GVS by aipteks regions.
I am happy with 2503, with my USA ver/ I have no issues but the premature low batt icon.
thedifference of 25 and 27 would not be much, what they are will be our guess
as Aiptek is secretive on this.
Thank you commission please