Well, I didn't get it to tether it with a phone, I got it for places where I have WiFi (home, friends).
It is not going to replace my N900, it's just going to complement it. So far, I am still getting used to Android (I don't like many things about it), but the device is pretty impressive. The screen is so big, and it's not heavier than the N900. And having working Flash is pretty cool too