Do I get same charging speed when I use a MacBook's usb port to charge my iPad?
From the Apple iPad Charging Support Doc.

The fastest way to charge your iPad is with the included 10W USB Power Adapter. Your iPad will also charge, though more slowly, when attached to a computer with a high-power USB port (many recent Mac computers) or with an iPhone Power Adapter. When attached to a computer via a standard USB port (most PCs or older Mac computers) iPad will charge, but only when it's in sleep mode.

Your 10W iPad charger (which is different to your iPhone / iPod charger) is the fastest way to charge your iPad. It is faster than your Mac or PC's USB port.