I don't own one but I have access to a couple of iPads at work and at home and I use them fairly often. It's pretty good for what it is. What it is NOT is a replacement for a full computer. It's fine for short emails, facebook/twitter, youtube videos, etc.
I suggest waiting a few months. There were some amazing tablets announced at CES a few week ago, like the Motorola Xoom.
YouTube - CES 2011: Motorola Xoom tablet (hands-on)
Also check out the Motorola Atrix smartphone. It's a phone, or laptop or desktop computer depending on which dock you put it in, pretty awesome.
YouTube - Motorola Atrix 4G Hands-On