Let me give you another reason why you should always use standard classes.It is because good design goes very deep
For example you can easily create your own implementation of a scrollview by animating the bounds property but there is no way you are going to come close apple's implementation of UIScrollView.It will take months if you try to make it from scratch.(I just spent a month!)
For starters you will have to understand the physics of it i.e the inertia,friction,damped harmonic oscillations etc.And even after that you will have to use a CADisplayLink timer to do the animations right by syncing them with the refresh rate of the display.
For example you can easily create your own implementation of a scrollview by animating the bounds property but there is no way you are going to come close apple's implementation of UIScrollView.It will take months if you try to make it from scratch.(I just spent a month!)
For starters you will have to understand the physics of it i.e the inertia,friction,damped harmonic oscillations etc.And even after that you will have to use a CADisplayLink timer to do the animations right by syncing them with the refresh rate of the display.