I ordered a computer from an online vendor. The computer is suppose to have 2 GB of DDRAM 2GB TWINX 2048-3200 RT by Corsair. I discovered on the day that the vendor was suppose to ship the computer that the memory was out of stock and on order. About 5 day have pasted and they still don't have the memory. However, they said that they can ship it today with Kingston memory. Otherwise, I will have to wait another week. What is the difference is performance and should I wait for the Corsair memory?