Most reviews for the PlayBook focus on the same issue: very few downloadable apps in app world. As a web developer - I couldn't care less.
Websites render fast, and due to the high dpi, look really nice. With its compact form, it fits well in my hands, easy to type and very portable. With a flash plugin included, streaming video is smooth and full screen works. Videos look really slick when plugged into a HD TV. Each app can only open one window, so the browser supports tabs and allows you to keep multiple tabs open at once.
Tabbed browsing works on the desktop, but not on the PlayBook. Only the open tab can be actively loading. Opening a new tab before the page loads can cancel the page from loading. Opening a new tab while watching video pauses the video. This makes watching commercials really frustrating because you can't turn away or it will pause. Watching videos in the browser is also frustrating, as after five minutes the PlayBook goes into suspend. (There are some tricks to stop this, but not if in full screen mode.)
In addition, despite all the fuss about multitasking, the PlayBook can't multitask. Most specifically you can only have one web page active at a time, and this includes webapps.
Surprisingly, the PlayBook is much less web developer friendly than I expected. The script engine is incomplete. There is no offline support for webapps. There is no support for turning a webapp application into a chromeless app. Webworks development requires a series of confusing bat commands that don't work the first time. All of this makes it really hard to develop for the PlayBook.
The apps I use include Browser, Wi-Fi Sharing, Word To Go, Slides To Go, Videos, Pictures, aVNC, and ReelPortal. All of them work, but I expected more from almost every one of them.
All that being said, I am going to hold on and put up with the current limitation of the PlayBook. I really like having a portable web browser, and I believe there is still a lot of potential for this device. I am looking forward to seeing what the next software update has to offer.