Q:

App works fine in iOS6, slow and jerky in iOS7

The development of this app had started in xcode 4.5 in August. The app basically consists of a view controller that uses MMDrawerController on the landing view. After this it has a tabbed control on the centre view controller, where each of the tabs create a new page view controller that render a data grid that has been created using TSTableView. While this app was tested on the ios6 simulator, it worked perfectly fine. The scrolling, swipe gestures, transitions etc. were very smooth and fluid, pleasing to the user's eye.
When xcode 5 was released, we upgraded and tested the app on the ios7 simulator. The behavior is quite jerky and slow. Scrolling the table results in very jagged flow of the rows across the view. Transitions between pages are also very sluggish, not smooth and fluid.
I have tried backtracking the code to strip it down to the bare essentials to test, but it still behaves the same way. However, when I tested the controls that I have used, they behave perfectly identical on both ios6 and ios7.
Can someone provide any pointers on where the problem might be and how I may go about solving the same?
EDIT: I have forgotten to mention a point which is mentioned in the comments. I did deploy it onto the iPad running iOS7. The behavior is exactly the same as on the simulator. Sadly I do not have a device running iOS6 to test it. In fact, since the simulator has much more resources at its disposal, it's performance can be considered to be far superior to that of an actual device.

A:

I have several tableViews and it seems as if those set with style UITableViewStylePlain are smooth as they ever were, but those with UITableViewStyleGrouped are jerky.
Some even have thumbs on the left side and they are just fine, but my settings table (it looks pretty much as the Settings of the phone looked in iOS 6) is rather jerky. It has default background and cells are either UITableViewCellStyleSubtitle or UITableViewCellStyleValue1.
On the smooth tableViews cells are created as UITableViewCellStyleDefault, then I remove all the standard subviews and put custom background view (with a gradient) and one imageView and several labels. Somehow this kind of tableView produces very smooth scrolling on both iOS6 and iOS7.

