no comment .........

I bought a grip for my 7D and it does add quite a bit of weight to the body.
but also gives me twice as many shots with it having two batteries.
It also is realy easy to shoot portrait as you dont have to get in a twist trying to use the shutter button on the camera body.

And as pointed out it makes you look the part
I would not be without mine now

Oh my!

Well I sooo don't have such an ego to feed I am sure

...and I do have a newish vertical foot long scar from sternum to 'erm infinity'.. to avoid bashing with extra weight.

I do take a lot of pictures in Portrait because I am 5ft3..

Well as Phil says..I can always take it off.

I'm sure you will think it worth having

You said the camera you are considering comes with a battery grip? So is it already built in such as a pro camera? Pro cameras sometimes weigh a little less than a semi pro plus a battery grip.

I find the grip very useful to counter-balance heavy lenses...handling is much improved and battery power increased. However, a semi pro camera, extra grip and a pro lens is pretty heavy going for a few hours out and about.

Third party grips from Ebay are a fraction of the cost of the genuine ones. Some seem to be just as good in practical terms.

BC is right. Depending what body you start with - Adding a grip can get the weight up to full sized bodies.

Nikon MB-D10 grip or Canon Equiv with 2 batteries is 400g

Canon 40D - 822g - 146 x 108 x 74 mm
Canon 7D - 860g - 148 x 111 x 74 mm
Canon 5D Mk2 - 850g - 152 x 114 x 75 mm
Canon 1Ds Mk3 - 1385g - 150 x 160 x 80 mm
Canon 1D Mk2 - 1565g - 156 x 158 x 80 mm

Nikon D7000 - 780g - 132 x 105 x 77 mm
Nikon D700 - 1074g - 148 x 111 x 74 mm
Nikon D3X - 1260g - 160 x 157 x 88

What do you expect?! I am always right... (unless the mrs says I am wrong!)

on most cameras your frames per second will also increase

So I hear, but I can't really tell to be honest. Not that I shoot many subjects in rapid mode......

Edit : Welcome to the forum, please excuse my bad manners

Don't call him that, call him Dave

Also make sure it's a genuine grip as some cheaper copies have got stuck on the bottom of the camera and had to be cut off.