The user experience has been drastically improved according to user reports, opening and scrolling through your timeline and completing most other functions has definitely got faster.
Facebook app developments
The previous app was built in HTML5 which had speed issues as the app had to download the users whole timeline every time they wanted to view, or review it.
Facebook are said to be investing heavily in mobile app development and are aiming to recruit up to 200 more engineers to code specifically for mobile.
One of the reasons for this could be that they are investigating how better to monetize the mobile user experience as this has been partly the cause of the massive drop in the price of Facebook shares recently.
It was discovered that a large amount of the user base of Facebook only ever access the website via their mobile device, with serving adds on such small screens being quite a challenge, the revenue from these users would be significantly less than a PC or Laptop user.