I have subscribed to be a lifetime member so I have access to the preview copy of the app. Hagarlucky is also a lifetime member and anyone else who is can post their review here. Currently the app copy is version 11, the submitted copy to Apple is version 4 but they are waiting for iTunes connect to get back up and running so they can submit their latest updated version. I am using an iPhone 3G
Each version gets more and more stable, they are releasing a new version every 1 to 4 days. Version 11 so far has worked quite well for me, they are some bugs when logging in that cause the occasional crash and a few interface bugs such as in the jump menu. Overall it is very stable and boots up quickly, it loads faster than the browser version. I have used it on Wifi, 3G and Edge and had no connection issues. The interface is beautiful they have found a way to provide full menu and button functionality without cluttering the screen, I was really quite impressed with it. The battery usage appears to be alright but it does use more than you would expect.
You can scan in the jump menu up to 600 LY now although I have looked and have not seen the Route Planner implemented yet. While the chat interface can cover a lot of the screen when the keyboard is up I think it is nicely implemented. Scrolling across the different maps is much easier using the multitouch iPhone screen, I am using a 2006 Macbook for the browser so I do not know if there are any multitouch control features available in the browser.
All in all I find the experience on the small iPhone screen much more enjoyable, the only real pain is the lack of multitasking between the app and safari, notes or anything else you would like to use as with the browser you can obviously have more open.
I give it a 9/10. It still has some bugs but it manages to deliver the full MMO experience on the iPhone with a full interface.