to DDR or not to DDR...

[Subliminal]

I just ordered 512mb of DDR from newegg.com and currently im running sdram (my mobo has 4 dimm sockets 2 for each type) but when I checked my order today DOH I had clicked on the 512 sdram which was only 50cents cheaper... Should I send the ram back and wait another week or two or should I stick with SDram (which would give me 640mb of sdr as opposed to 512 if i went with the DDR). I cant decide.