I bought the grip, "Re: You really need to learn to hold the camera properly." I have a very good idea how to hold the camera having worked with them most of my life, and that's a very long time. I wanted more, I wanted it better. One thing I was quite proud of was how smoothly I could hand hold motion picture cameras making the shots look as if shot from a tripod with a fluid head.
I put a grip on my camera in the store with my 70-200 2.8 on it and wow, I started taking photos of the salesperson, very smooth, very solid, and yes very heavy but the balance was so sweet that it tood about 20 seconds to forget the weight.
There will be times I will take it off because of the weight and because it does make it look so "professional" which is a big detriment for a lot of what I do, I would be shooting an XTi if it had the same quality as the 5D. The last thing I need or want is to try to impress anyone with the equipment and I've been working behind a camera long enough to where the only think I'd ever care about you being impressed with is more about appreciating my photos, impressed or not.
I just picked it up to practice a bit, I'm tired, it's hot and I'm also pretty frustrated about some other things today but I started shooting at first 135mm/1/30th sec @2.8 and chimping in and got a big dose of wow, so I started going around shooting at 200mm, 1/30 sec and 2.8-I'm amazed, very good, not quite excellent at that length, there only seems to be sharp or not sharp, really no grey areas at all, but it's new I've only got a dozen frames on that camera with the grip but it makes a huge difference to me. I'm going to go practice now with the IS turned off and see how well I can do.