The only thing that's keeping me from buying 4850CF is the thought that a 4870 with GDDR5 could be beneficial later on (since the 4850 only has GDDR3). Is it really going to make that much of a difference?
the GDDR5 can clock higher than the GDDR3. i'd get the 4870 and crossfire it l8ter with another 4870.
Or if you could spare the money wait a little bit and grab a 4870x2
it all depends are on how much have. GDDR5 is worth paying for. Also remeber if you do want to buy a better video card u would probably also have shell out for a better psu