Link to the article by Richard Gaywood .

2013 Nexus 7 Wiki for reference.

Richard draws some great conclusions and keeps a very open mind while explaining his biased starting point as an iOS user. A few key items for me:

Pros:

Emulators, app data sharing, inter-app-erability (you heard it here first... err second) open the door to complex and interesting apps and use cases.
Changing defaults (mail, browser, keyboard) really allows the device to be tailored to fit the user.
Voice recognition:

"It's like night and day compared to Apple's offering. If you've never seen it, find someone with an Android phone and try it out -- then think about how much more often you'd reach for Siri if it was this good."

No credit card required to setup a Google Play account. My initial thought was surprise that you still need one for iTunes, however my second thought is how much more seamless of an experience obtaining content is with a credit card on file. Like it or not, it makes enough sense that it won't be changing.

Cons:

Nexus 7 had a "cramped" web browsing experience, often used mobile sites to work around this.
He sorely missed Tweetbot. I too ranked this among my least favorite things about switching to Android (clearly not Google's fault).
"Fewer interesting games on Android"
Fewer calendar apps. If I had to guess, I'd say it is due to lower corporate adoption or the lower spending trends on Android (good calendar apps are rarely free).
Inconsistency, eg. the back button:

"About 80% of the time, it did exactly what I thought it would"

"Jefky/laggy/hesitent scrolling" on a device with a quad core CPU and 2GB of RAM and Adreno 320 GPU this seems unacceptable. Especially given it was within Google's own services.
Duplicate versions of apps in the Play Store and needing to install a plugin for an app to work (BBC iPlayer) makes for a poor user experience.
Seeing this request for permissions when you install a new keyboard is scary:

...third party keyboards could "see anything you type, including passwords and credit card numbers"

As long as that data isn't sent off your device or stored in any way, it is totally acceptable.

His closing "update" highlights a fundamental delta between OSes:

One striking thing, as I have noted in some updates throughout the body of this article, is how many of my observations can be addressed through third-party apps that would be impossible on iOS.

This ended up being longer than I had planned, but everything above stood out to me. Clearly a highly personal choice.