I had the Wi-Fi only version that I tried to use with the Overdrive.
The Overdrive was crap.
I was successful connecting to other MiFi devices, but the Overdrive always gave me sub-dial-up speeds and/or faulty connections (even with the Overdrive firmware update).
So, for me, it was the Overdrive, not the iPad.
I actually never understood the outrage over the "Wi-Fi issue." I never experienced problems anywhere or with any device other than the Overdrive.
I returned the Overdrive.
The Wi-Fi iPad is now the Family iPad, and I use a 3G full-time and rarely use the Wi-Fi unit, but, we're still experiencing problem free connections when we do.