So, I'm new here and I really don't know a lot about Android but I thought I'd jump in with my thoughts because I do have (or have had) all of the tablets listed. 

Currently I have:
iPad 3, 32gb
Nexus 7, 32 gb
Kindle Fire HD, 16gb

All of these devices are wi-fi only. 

I also have a 3G Kindle Keyboard ereader and a 64gb iPhone 5. 

I have HAD a Samsung Galaxy Tab, but I didn't like it at all so I don't remember specifically which one it was. 

Anyway, I get that this is the Nexus 7 board, and a lot of people love it (and Android in general).  Which is great; I just got my N7 but so far it seems to be a pretty decent little tablet.  I get the Apple-bashing; we all want to be loyal to the platform we chose.  In my experience...and I've had every iPhone since the first one...there is NO better customer service than the people at Apple.  Every issue I've had has been quickly and painlessly resolved for me so I'll be sticking with them. 

Also,  speaking of customer service, Amazon is a close second (they may even be tied).  Again, I've dealt with Amazon for years and have never been let down.  This is the reason I initially went with the Fire tablet.  I purchased the first one, but decided I'd rather have an iPad, so I sold the Fire.  A few months ago my company started traveling me around and I wanted a smaller device to carry on and off planes easily so I got a Fire HD.  It does everything its supposed as far as keeping me entertained during a flight...books, videos, music.  However, I'm not really a fan of the locked down Amazon system and I hate the carousel.  I wish it were optional; some people like it, but I'd rather set my screen up the way I want to.  Every book I order from Amazon goes to the Fire, whether I direct it there or not.  They are easily removed, but I'd rather not have to bother with it. 

I know there are those that hate the Amazon ads, but that doesn't bother me.  You only see an ad on the lock screen; its gone as soon as you swipe to unlock so its no big deal.  They do say that the ads reduce the price, but the ad-supported verson is $199, while the one with no ads is $214.  That's not in line with the N7 and could make some people cranky when comparing devices.  The recommendations ("customers also liked...") can be turned off in settings, so those are a moot point.  The Fire HD is a terrific device for media consumption, but not so good at productivity.  As others have mentioned, the browser is not the best.  and I never really used it for anything besides video or reading.  My iPad is far superior for working/productivity. 

So, why do I now have an N7?  Well, for one thing, I'm attracted to little gadgets like that and have heard good things about the N7.  I was intrigued by it and had a just received a small bonus so thought why not.  As much as I love iDevices, the iPad mini seemed redundant to me, plus I still wanted my baby tablet to be somewhat of an entertainment device.  I specifically wanted a 'droid tablet because I use the app Droid TV a lot.  The Fire HD has proven itself to be a great tablet in that respect, but I also want something I can do work on, if needed.  My company is just about to release an app for our employees to use in the field, and I want to be able to take advantage of using it. 

I know this is rambling and you are probably wondering where I'm going with this.  To be honest, I have no clue!  I started this hours ago, and I'm sure I had a point, but I keep getting pulled away and have no idea where I was when I started.  So, I'll just list some of my initial impressions of the N7.

Its narrower than the Fire HD so it fits in one hand better
No carousel, which is good
I can set up a screen full of app icons, just like on an iPad
I don't "get" widgets; how are they better than just clicking an icon?
I like the iOS email program better
Why does everyone love Swype?

If you made it to here, thanks for sticking with me!

Edit: glaring typo (there are probably others)