HiI had my computer built around 1 month ago with an i5 2500k and did specify the gtx 560ti graphics card. He had none in stock so let me have a gtx 550ti 2Gb as a replacement until one comes in.However he now cannot get one and has offered me a sapphire 6950 IGb. Should I keep my 550 which I think is great or swop to the 6950 ? Or is it worth upgrading to gtx 570 ?Thankyou.

Well before I bought my PC I did a lot of research and came to the conclusion of either the 560, 570 or the 580, which is what I went with. All the good vids on YouTube I've seen are running these cards.

Well, the 570 is likely overkill to FSX. A good 560 or560Ti will be just right.