Well I initially got the iPad as a reader... i got some ebooks for college and everything was so simple on the iPad [nothing like a traditional textbook, but when you are saving hundreds of bucks, who cares about hardcover, huge textbooks!!. That was my sole purpose- educational...
Yeah, that didn't happen (for the most part)... slowly I entered into the world of game,s internet browsing, and trying out apps (lolz). Right now, I spend majority of my computer time on my desktop, a huge chunk on my iPad and very / almost none on my poor MBP... I went as far as purchasing a bluetooth keyboard ( it was on clearance -about $9 bucks OTD- so it wasn't a terrible price).
I still use it for education (haha you know, playing games while listening to lectures, jk) but it's mainly limited to reading the e(text)books.
My advice, this one is a tough one as your only use seems to be magazine and reading. IMO, i would say go for 3, you certainly would appreciate the retina display, and since you have played with the iPad 3, I' have a feeling you wouldn't really like the iPad 2's screen for reading (but if you are keen on buying an iPad, you would want to check both iPads out and see which is too your liking)
Hope this helps!
Happy Hunting!!