iLounge was able to run a few tests on the microphone housed in the new iPad 2 and found there's a noticeable difference in quality between the Wi-Fi-only iPad 2 and the Wi-Fi + 3G models.
When using Skype and Garageband on the iPad, iPad 2 with Wi-Fi, and iPad 2 with Wi-Fi + 3G, we found that audio from the 3G iPad 2’s mic sounded somewhat more muffled and echo-prone than with the original iPad’s or the Wi-Fi-only iPad 2’s mics
This is due to the microphone being moved from next to the headphone jack on the original iPad to a top-center position on the iPad 2. The Wi-Fi-only model is fully encased in aluminium where as the 3G models have a plastic strip along the top which has an impact on recording quality.
Have you noticed a big enough difference in microphone quality between models for it to actually mean anything to you? let us know your thoughts in the comments!