I own both and posted this recently in a similar thread on Crackberry following the same topic:
"I have to say the N7 is the tablet I had hoped the PlayBook would be when I bought it, then when they updated it and promised Android apps to fill the void (which didn't), and now with 2.1 I still cannot do things with the ease of use I can on the N7. I can site a few examples:
1. I am sorry Skype is important to me and I use it on the N7. Is it perfect, no. But it's better than the alternative on the PB. I travel for business and it's nice to take the Tablet on overnight trips and leave the laptop home.
2. I am a sports fan. I get the MLB and NHL apps and watch the games easily on Android. Unfortunately with the NHL strike I can't say how well the games work on the N7 but the MLB games are great and with the MLB app for Android it's easy to go from game to game and look in and see whats up. I play fantasy baseball and it's a nice way to check up on my team even when I am sitting on the couch and the girlfriend wants to watch a movie or one of her shows on the big screen, oh Miggy Cabrera is up lets see what he's gonna do...Can't do that easily on PB and by the time you did probably too late. You can't watch baseball at all on the native browser, hockey either. There is a "work around" using simple browser but it's virtually impossible to flutter in from game to game.
3. I know there are ways to side load popular apps like WWF and Kindle but my experience with multiple Android apps on the PB has been a PITA - though I am going to give PB another chance now with 2.1 and see if the ability to open multiple Android apps is any better now. I had taken the Android apps off PB but I am devoting Saturday morning to giving it another go and reload. However, it goes without saying if I want to go from WWF to Kindle to the Baseball game back to the Kindle its super easy on the N7 just hold the home key and go from app to app.
4. This one probably isn't fair but I use Google services a lot and GDrive, G+ and GMusic just work better on Android. Box or Dropbox is fine for somethings I like GDrive better. Personal preference.
Those are just a couple/three/four instances that come to my mind - I am sure I can find more if I want to. I believe those who say that "email is better on the PB" I not sure I understand what you mean. Both use the same ActiveSync and they work virtually the same IMHO. We use a MS Exchange server and I guarantee you I get my email on the N7, my 9810 and my PB at about the same time mas o menos and they all allow me to do most of the same things, the PB and N7 are virtually identical in the way they deal with email. I also have a POP personal account and feel the experience is identical. I can't speak for IMAP.
I sideloaded Flash and simply with FireFox beta have no troubles watching Flash at all not sure what troubles others are having, and I love the ability to sync Chrome to all of my devices I wish we had that ability on PB, not to mention I like the way Chrome uses traditional tabs in the browser I am not a fan of the way the PB browser does it.
I have my PB until BB10 comes out because I believe that finally after 2 years BB10 will solve many of my problems and I will finally see a BB tablet that I had hoped I would get when I paid a lot of money for the PB back in Nov 2011. I have been a vocal critic of the PB in this forum I believe the device has so much unused potential its really sad the PB had to take a back seat while RIM goes full bore on BB10 (which I understand and support - PB was wrong place wrong time)."
And when someone can convince me the need to have 3 or 4 videos playing at the same time I will concede the point to PlayBook but my N7 runs 2 just fine. PB uses Android 2.3 for it's emulator as well and is wonky at best on the PB and outright unstable at worst.