Seeing as how I didn't have a tablet until recently, I was never able to actually give Honeycomb a try. I've spent the last few days using it on my Nook, however, and I can finally give my opinion on the latest version of Android.
Note: Since Honeycomb has been out for quite a while and multiple publications have covered it extensively, I won't be cluttering this post with lots of screenshots. For some very nice, high quality screenshots of Honeycomb in action, head over to Droid-Life.
Unfortunately, Google has yet to (and probably won't ever) release the full source code for Honeycomb, meaning all the hacked versions for devices like the Nook are imperfect. On the Nook, for example, there are a number of things that don't work, or work partially. So for me, it's not good enough to use as a daily OS, both because features are missing, and because using it eliminates the excellent Nook reading experience. But even though I'm not using it full-time, I have still used it enough to get a feel for it.
The main homescreen of Honeycomb is a huge, drastic departure from the Android experience on a phone. Everything is designed for a large screen and rearranged to work better with more space. Even the lockscreen is revamped to avoid super long swipe lines, which tablets running other versions of Android have to deal with.
The same way Gingerbread brought lots of green theming, Honeycomb brings blue. The whole OS has a blue TRON-esque theme that permeates everything, from the icon outlines to the loading animations. It doesn't look bad, per se, but it definitely takes some getting used to. It almost looks cartoony, but in a refind sort of way.
Honeycomb does away with hardware buttons entirely, instead opting to put the traditional Android buttons in software along the bottom left of the screen. There is also a text and voice search area always available in the top left. Apps are accessible from a screen button in the top right, where there is also a button to add items to the homescreen.
The app drawer is arranged in full pages that scroll horizontally, much like the iPad. Apps can be sorted by All or Downloaded which shows only the apps you've obtained from the Market.
Speaking of the Market, both it and the other Google apps have received major facelifts as well. The Market itself looks nearly identical to the Market website, while Gmail shows multi-pane viewing, label lists down the side, message previews, etc. The YouTube app has also been revamped to better take advantage of the bigger screens.
The Browser, too, has gotten a big screen feature-boots. It now looks very much like Chrome with tabbed browsing, etc.
Not using Honeycomb as my daily OS on the Nook limits my ability to get a strong feel for it. I can make observations, of course, but I won't be able to find all the little nuances (both pro and con) that make up using a device on a daily basis.
That being said, I really like what I see. Honeycomb makes much better use of big screens than Gingerbread does. Things like multi-pane Gmail and apps like Tweetcomb that really take advantage of the space are what really make the OS shine. I also really like the on-screen buttons instead of hardware buttons. I don't know why, but they just seem to flow better.
As much as I expected to like the TRON themed blueness of Honeycomb, I'm not entirely sure I do now that I've played with it for a while. Don't get me wrong, it looks very cool and futuristic, but there's just a slight twinge of an unprofessional, childish, cartoony vibe in there. The same way you might be embarrassed to use your phone in public if you had an cartoony wallpaper image, Honeycomb makes me almost (not quite, but almost), hesitate to use it out in public instead of the stock OS.
Honeycomb also has a bit of a learning curve that something like the iPad doesn't. It makes things like search, apps, settings, homescreen customization, etc. very easy to get to, but the buttons are all on opposite corners of the screen. It looks nice, but for someone not used to it, you'll find yourself doing a lot of hesitating while you refresh your memory with where all the buttons are.
On the whole, I can definitely say that Honeycomb is perfect for tablets. I'm almost glad that the effort to hack it to work on phones has been limited, because this just wouldn't be a good experience on a small screen. On a tablet, though, it rocks.
It's a completely different experience from the Android we've been used to for the last 2+ years, so for Android enthusiasts like myself, it sure takes some getting used to. Everything is still there, but it's all been moved around, features added, buttons removed, concepts changed, and just overall very different. Once you've played with it for a while, you start to really appreciate the big-screen changes and miss them when you go back to a smaller screen.
I can honestly say that if I were in the Market for a 10" tablet, Honeycomb would be a requirement. Things like Flash in the browser, real multi-pane Gmail, resizable widgets, etc. totally push it over the other tablet options out there at present. If you're looking for one, you definitely owe it to yourself to check out a Honeycomb tablet before making your purchase.