I have the D700, grip, 24-70, and 70-200. I don't have the 14-24 or the D3, and have only owned the D700 for 11 days. I do, however, have an opinion (doesn't everybody?).
I think the D700 without grip and the 24-70 are a perfect match, the combination feels well balanced and natural in my hands.
The 70-200 on the D700 w/o grip is a slight bit overpowering. It does not feel uncomfortable, just a tiny bit unbalanced. I find that adding the grip to the D700/70-200 combination feels better to me. Please don't misunderstand, I use the D700/70-200 combination without the grip most of the time. I don't find the grip "necessary" with this combination, just slightly more balanced.
I think you would really notice and appreciate the size/weight difference for general, everyday walk-around shooting. My previous bodies were 2 D200s, one with grip and one without. I found that for my style of shooting the D200 without the grip was used 90% of the time. Most often I like to carry 1 body and a few lenses/accessories in a backpack, just looking for something interesting to shoot.
The D700 is the best Nikon Full Frame Sensor option for me. I get the smaller, lighter body with an option to add the grip when appropriate. If I know I will be shooting mostly portraits the grip goes on. The D200 grip was just too much of a pain to add/remove to make this a reasonable option.
Just my opinion, but I hope this helps.
I never have taken a picture I've intended. They're always better or worse. - Diane Arbus