The Next Web and Business Insider have more in-depth reviews.
The app is $2.99 and is a separate purchase from the iPhone app, a fact some users may dislike, but Tweetbot co-developer Paul Haddad explained his thoughts behind the pricing strategy to Business Insider:
People complain that it isn't $.99 or free. But we never said we'd make Tweetbot universal. If you look at the other paid universal Twitter clients they are for the most part $5 and I think we have more features than those, so we're comfortable with the pricing and having separate apps.
Also released today was Tweetbot 2.0 for iPhone, bringing updated timeline, direct message, and reply views, as well as a number of other smaller changes. It's a solid upgrade that's free for current Tweetbot for iPhone users.
Tweetbot for iPad is available for $2.99 from the App Store. [Direct Link]
Tweetbot 2.0 for iPhone is available for $2.99 from the App Store. [Direct Link]