Ahh I wish I could make my mind up, and get the funds to buy a fullframe SLR, Torn between the Nikon D700 and the canon 5d mkII, the 1.4 version would be fab on the d700.

It's fab on the D300 too! Full frame will come at reduced cost. It's just in that transition period where they attract too much of a premium right now. The D700 and D300 are very similar yet Nikon are happy to maintain a £700 gap simply because of the sensor size and what they want it to mean. It is worth making your mind up which way you want to go though as it will cost later if you want to change. The race between each manufacturer will see both nudging ahead from time to time so it doesn't make too much difference. As Nikon user though I couldn't be doing with all that delving into menus to change some settings that Canons seem to require.

50mm's are lovely lenses, if you have the f1.8 you can be perfectly happy, but the f1.4 does have the edge.