Terry, after being on the fence, I went ahead and did the update. It went through with no issues at all. However, based on some of the comments I read here, I deleted all widgets and app shortcuts from the Tab 10.1 and restarted the device before I started the upgrade. From download to installation, the whole process took ~20 min., which seems to be normal for most people.
A few quick initial observations:
I personally have not noticed any significant increase in performance. That said, I have not noticed a decrease in performance.
Pictures in my gallery/Picasa definitely seems to have a much better/sharper display. I was never happy with the way pictures displayed on stock. With TW, they are beautiful! Seriously! Maybe there was a display setting in stock I needed to change...Tilt to zoom is cool. Kind of a neat bell and whistle to show people, but I am not sure how much use it will get.
Browser does not seem faster to me either. Bookmarks disappeared, as most have indicated.
Swype with keyboard is nice. Meh...
Mini-app drawer...I would only echo comments that have been posted about it already.
I have not tried it with the keyboard dock yet.
From Samsung's perspective, I can see why they did this. They can differentiate Honeycomb compared to the rest of the HC tablets on the market.
Overall, I do not think it drastically changes the user interface significantly. I pretty much rebuilt my screens as I had them before. I tried out the weather live panel widget, but I have been using the Beautiful Widgets weather and clock and went back to it. They both use Accuweather anyway. Now I can get future updates to the device.
Hope this info is useful. Let me know if you have any other questions and best of luck with your decision.