The biggest advantage of the 3 GB model is not so much a performance increase over the 1.5 GB model, in fact they deliver the same performance, UNLESS:
You use large pixel dimensions and there comes a situation where all VRAM is used. Then the hardware MPE engine is completely turned off and is reverted to software MPE and the program does not warn you about that, at least not explicitly, but in performance. When that happens, you will automatically lose the maximum render quality too, unless that was checked before the export started.
Todd has written a blog about the pixel dimensions where that happens, but I don't have the link here, so do a search.
If I were to choose today, even though I don't use RED or large stills, I would get the 3 GB model, because in the future, when pixel dimensions grow and grow, I rather have some breathing space.
Hi Harm and Jim. Thanks for this fantastic input.
BTW, i cannot register my Adobe account presently, perhaps the site's being
refurbished...feeling miserably alone as such:(
There appear to have been problems (again) all over the place. I for one know people in Canada that had problems logging on while I had no serious problems, apart from the response time, and others in the US had problems posting reports.
Regularly Jive gives me the jives with the very old version in use and, as an analogy, it sometimes looks as if Adobe is promoting CS5.5 but is still using Premiere 6.5 itself.
Over in http://forums.adobe.com/community/general/forum_comments Adobe-Admin has mention that "sometime" this year the forum software will be upgraded (I think to version 184.108.40.206) with an ETA of September