Should I buy a 2012 Nexus 7? Or a Nexus 7 at all?

Googleplex folk!

I've decided I want a tablet. I'm investigating iPad options (I own a Macbook and iPhone, so it makes sense). But, I keep seeing great deals on used Nexus 7s, around $130 for the 2012 model, and around $170 for 2013.

My uses:

- Reading! Textbooks, code/programming docs, PDFs

- General browsing, Reddit, Feedly

- Some light Gmail, Pocket, design inspirations, Pinterest

Not looking to do a ton of content creation. The one that I'd be missing is iTunes U, which looks really interesting and something I want to get more into using.

My questions:

How does the 2012 stack up against the 2013 model? Will I hate the lower screen resolution, or is it a case of 'as long as you don't use the higher-res one, you wont know what you're missing'

Do you find the screen too small? Portability isn't a huge issue with me - I already have a 15" 2012 Macbook Pro, so adding another 2" to a tablet (iPad vs Mini/Nexus size) isn't going to make a huge diference.

How does the Nexus stack up against the iPad? How's your real-world experience been?