Ok, the main differences between those 2 models are listed below:
AcuSense: DS-2DE7432IW-AE(S5) - supports AcuSense / DS-2DE7430IW-AE - Does not support AcuSense
IR Range: 2DE7432 - 200m / 2DE7430 - 150m
Optical Zoom Range: 2DE7432 - 32x (4.8mm to 153mm) / 2DE7430 - 30x
Most importantly though, from our digging for these specs we have found that the DS-2DE7430IW-AE model would appear to now be End of Life.