Correct me if I wrong ... but doesnt the human eye only read about 40fps. So there would be no way to "see" the difference between 40 and 100fps. So if your machine is getting anywhere from 35 up... a new machine with more frames isnt really going to help much.
Going to a High resolution may help, which a new machine could do, will give better eye candy and might aid a little.
I have my Frames per second limited to 45, As I understand... when in the thick smoke your computer doesnt have to attempt to draw more than 45, so you have a better chance of maintaining decent frame rates. That might be rumor thou.
Iv got AH running on few machines of Various speeds, I dont see a huge difference between them. Iv also done H2H over the Lan and there is no speed differnce between like planes.
I dont think a better PC makes you a better pilot, It really comes down to basic skills and SA.
I noted the plane types, both are excellent planes for watching for a safe kill. Id guess that would be the reason your dying less. And if you flew them before, then perhaps your judgment is better and your SA is better.