Yes, we did. I still have 3 weeks to return it, but it is unlikely that I will. I do agree that the one thing that annoys me the most is tethering shuts off the WIFI. I never even thought about the Ethernet jack. To make something this small work as well as it has for me, there have to be design compromises.
As far as being a locked down device goes, I have fallen into that trap we often do with technology. As much as I loved whatever cell phone I have gotten at contract time, only once has a device survived renewal. Since the MIFI is a company provided device, I am afraid I have regarded the $100 as disposable, like my Treo. We live in a disposable world.
If it makes you feel any better, my car is 9 years old and has 120,000 mi. on it.
PT