I was lucky enough to be on the Beta list for Remember The Milk for the iPad. Until now, I've been sworn to secrecy, but it's now in the App Store (as a Universal app), so now the embargo is lifted.
I've been a long time RTM fan. I had drifted away to other solutions when I first got the iPad, due to there not being an iPad app (and the web app didn't work well on the iPad), but now I'm back :)
The app has everything that long term RTM users will be looking for. It works well in both landscape and portrait modes and takes full advantage of gestures and general swipey goodness.
Thanks to the Quick Entry bar, it's very easy (and quick!) to enter new tasks. Marking items as complete is as simple as selecting an item and tapping the tick mark. There's another option, which is a two-finger swipe down on the item, and then another tap to "Complete", but this is too many gestures for my liking. I was also a little disappointed to not see my request for a simple check box next to each item which you could tap to complete it.
There are some "interesting" fonts in use. Initially, I wasn't too sure about these, but having used it for a few weeks, they've grown on me and I now quite like the quirkiness of it - it adds a fairly unique look to the app.
I'm now back to RTM as my main To Do manager. With the ability to maintain the data via the web, iPhone and now the iPad, I have all my To Do's with me at all times.
It's taken quite a while for them to get the iPad app done, but it was worth the wait. A thoroughly recommended app.