For 3-way Power

For me personally for large cameras the vertical grip for two reasons a "must" - First, I have so several batteries in the camera (as opposed to 900 or 77er handle the battery can remain in the body), secondly, for ergonomic reasons, I straps only to bear likes and I can as a wrist strap, comfortable carrying attachment.

The main elements are the vertical hold available, and the grip is just as high quality as the body itself.
The battery, which can remain in the body, is used only if the other two are empty. Since neither the A99 nor here at the VG-C99 AC adapter is included for the camera DC-in, you have to unscrew the handle to charge the batteries in bodysuit. That's a little cheeky by Sony, since the power supply a suggested retail price of 99, - Euro has.

Here's my review in brief:

++ Workmanship
++ Ergonomics and handling
++ Sealed against dirt and moisture
++ Many important controls available in vertical holding on the handle
++ Controls on the Grigg can be switched off
++ Battery in the body does not need to be removed, so you have three batteries in the camera
o No ISO button available separately
o Price about 1/3 too high

All in all I do not want to miss the handle. For my needs 100%. Thumbs up and five stars.