If you don't like the online services and won't take the time to sell on eBay or Craigslist (not sure, but based on the fact that it's not an instant sale it seems like it may be too slow for you) you likely ARE going to take a hit on what you can get by needing the cash that instant.
There are no ways to easily sell an iPad instantly that don't involve selling to a retailer that needs to make a big profit on it to make it worth their while.
Gazelle, on the other hand, may take 7-10 days to send you the funds, but will almost always give you more (in cash at least).
Personally, Craigslist is your best bet. Yes, if you meet Shafiqua on the corner of Nowhere and Ghetto at midnight to consumate the deal you might get robbed, but as long as you aren't moronic (and desperation for cash leads people to do dumb things so I say that in fairness), you'll be fine.
Meet in a safe place. Sell. Get your cash.
You can see what they're going for in your area and price accordingly, but the lower the price the faster the sale (generally).