Well I have the 47Ai never had the 45A but the 47Ai has much better specs and henceforth the image should be better:
47Ai:
Video Digital/Analog Converter (DAC): 108 MHz/12 bit, for high quality DVD pictures (Analog Devices)
Super-Fine Focus Filter with 4:4:4 Video Up-sampling
Video Parameter Adjustments: 16 adjustments w/3 User Memories (Progressive Motion, PureCinema (on, off,auto), YNR, CNR Mosquito NR, Block NT, Sharpness High, Sharpness Mid, Detail, White Level, Black Level, Gamma, Black Setup, Hue, Chroma Level, Chroma Delay)
45A:
Video Digital/Analog Converter (DAC): 54 MHz/10 bit, for high quality DVD pictures
Super-Fine Focus Filter: does not have!
Video Parameter Adjustments:7 adjustments w/3 User Memories (Fine Focus, Contrast, Sharpness, Brightness, PureCinema (on, off, auto), Hue, Chroma Control)
3 Factory Video Settings CRT, PDP, Professional