Thanks for your feedback! Let me get a little more precise on what I am looking for:
Q1: I would be using the new MBP 15" in mobile setting (all things equal). Usually "mobile" would mean "no heavy lifiting" on graphics as you pointed out entirely right:
>> Would the simple fact of 256 (vs. 512MB graphics) suck less on my battery, and I could count with about 3-4 hrs (web/office)? (vs. less than 3hrs with the 512 option?)
Q2: Would the 256MB produce less heat when barely used, compared to the 512? Or is there no difference to be expected when used similarly?
Q3: ..and that one actually stems staright from your advice: would heavy lifting drain a 256MB 15" MBP more than the 512, or less?
Thanks again for all feedback!!
For mobility, my best suggetion is to get macbook. but if you still want a MBP, 3 hours maybe good, 4 hours i think is pushing it. If you used the whole 256 vram, most likely you will not get to 3 hours (i am kind of skeptical if it can reach 3 hours). 512 is even less, Apple's battery is nothing special. It is the same as PCs.
Q2: the heat i think you should be more worry about is the cpu. Cause thats the part thats running the whole notebook. In my experience, do not ever put a MBP on your lap. it burns!!!
i think there is an argument out there why apple name their notebook, notebook not laptop. Its because it cannot be place on your lap. As far as the graphics, i think it does not produce as much heat as the cpu. Cause the more graphic you use, the more cpu you use.
Q3: i think it will be about the same cause if you use 64mb of vram in 256 graph card, its the same 64mb of vram in 512 graph card, but, if nvidia has created something more efficient in power usage, that might be the difference worth checking it out.