Although I don't have a Tab, my S7 is also a 7" form factor. After a 1-1/2 months, I love it. The size is just about perfect. I can slide it in a pants pocket (while upright). It easily fits in my inside coat pocket. Although it's the same resolution as my N900, I rarely use my N900 for anything more than a phone now. It's so much nicer looking at the larger screen.

It's great for navigation, got a cheap rocketfish window mount at bestbuy, sits wonderfully on the dash, doesn't hardly block my view at all. Easy to glance at and quickly see where I'm at, etc without straining/squinting at a smaller screen. Although, I'd love to see a better navigation interface designed for the larger screen.

Even at 10", I don't think any of the current (or even next gen) tablets would really replace a laptop/desktop for power use. At least for me, traveling doesn't require much on the go work, so 7", being more portable is ideal. I think 10" would just end up sitting at home, sharing time with a laptop/desktop, and wouldn't see much on-the-go time. 7" is really easy to grab and go right now.

snoshrk:

Go to best buy and check out the Huawei S7. It's got 3G (AT&T) voice/data, no contract required, GPS, and full Marketplace, hardware buttons, 1Ghz cpu, 512MB. Downsides: It's a bit heavier, smaller battery, 2.1 (although 2.2 is supposed to be this month), resistive screen (not a big deal), and 800x480 resolution. Basically a giant phone. But at $250 on sale ($300 normally), I think it's a decent deal, especially if you're unsure about a tablet.