Do MB-D12 owners feel that MB-D12 is worthwhile?

I have a D700.
I thought that I would not benefit from the handgrip MB-D10.
And I thought I did not really need a higher frame rate for family photo.

But ultimately, I bought it.
It was so nice.
It is good to use in portrait position.
I enjoy using it very much.
The extra battery also prolongs the usage, gives me secure feelings that
it's not going to run out of battery any time soon.
And I can occasionally do silly high FPS with fun. Since it's free, might
as well use it.

Do MB-D12 owners feel that MB-D12 is worthwhile?