Twitter now lets marketers access every public tweet ever made

This is pretty much what Gnip offered, but with an usable API.

My company did request an historical sample to GNIP one year ago: we had to contact the sales and send them a query blind-written following their docs. Then they run a job and gave a link to download the ZIP. I can imagine high paying customers to have direct access to their API. Still it was pretty much evident, than the extraction time was significant (say from 1 to 3 days).

The main difference thus appears to be speed. Still, you need to contact sales, so I can't say nothing about the new prices.