AT&T's 32 GB 1520, worth it?

Internal memory is always more efficient but aside from this if one plans on selling the phone when they're done the 1520.3 will sell for more as supply vs demand will be in their favor and the at&t version will be a dime a dozen by comparison. So it really comes down to. Do you want qi? And can you afford to pay up front?
 
You can get a 16G refurb for free from AT&T, to me that's worth it any way you slice it.
If you mean that it's free on a 2-year contract, know that the contract price is $15/month higher than the Next or month-to-month price. That means that the refurbished 16GB AT&T 1520 is really costing you $360 spread out over 24 payments. That's less exciting than free, but it's still pretty cheap.
 
If you're getting the AT&T version, what would the price different be between the 16gb version and the 32gb version for you?

That would be the only difference, and with 8.1 you can install apps to the SD card, so it's not really that important of a difference beyond price.
 
Also want to add that I got my 32GB model on Ebay, brand new for 420 bucks. Black model by the way. If you are still thinking of getting 1 check on there for a good deal. For 400 bucks, you can't go wrong with this phone.
 
The Lumia 1520.3 at B&H Photo is $490, has 32GB, Qi charging, and a U.S. warranty. However, repairs will be via a mail-in since you can't stop by an AT&T store. The B&H purchase will likely be sales tax free, so that might save another $30-40 on the cost when purchased from AT&T.

The US warranty part is absolutely wrong. See this return letter from Nokia when I asked for warranty service on my 1520.3.
NokiaNoWarranty.png

In the end, I was able to negotiate with Nokia, claiming that it was wrong for the site to proclaim "in warranty in the US" on their warranty checker page putting in my phone serial (I'm not concerned about exposing the serial in that pdf, I don't have the phone anymore), so they decided they would be able to make an exception and trade me for an AT&T 32GB edition of the phone. In some ways a downgrade (wireless charging), and in others, it just plain works (internet sharing) without any tinkering around with Spanish Spain keyboards (which seems to be patched in WP 8.1) which is a relief. I've also experienced the oddities of flashing the French CV firmware to my Lumia 920, so I'm really starting to appreciate the "just works" firmware on AT&T devices.

I hope this helps you decide. There was a time on AT&T's website that you could choose 32GB but only if you picked black. That option seems to be gone now. I'm OK with black (was a yellow 1520.3), but you may really enjoy the color options.
 
This is great to know the proper warranty information. I, too, made my 1520.3 purchase decision in part on the word of others who checked the Nokia warranty site and mistakenly thought that the device would be covered in the States. Thanks for posting the correction!