Joesixpack00 probably meant that Intel has the performance crown (i7), but when it comes to bang for buck in more reasonable market segments AMD wins, especially with Phenom II processors.
It takes fully charged body shot to one-hit kill you and you can't aim that well when you're on the run from that shot.
Yeah, soldiers can be really annoying for snipers, I don't see many of them harassing them though, at least on the public servers.
Run it in DX8 mode. You loose shader effects but it runs leaps and bounds better on hardware of this class and doesn't actually look much worse. One of the computers I'm playing TF2 on has Athlon64 3500+ (single core), 1GB of RAM and GeForce 6600 (not 6600GT, big difference).
Spies have better things to do which makes snipers the only viable countermeasure for other snipers. That's a problem IMHO.
Meet the low-poly TF2.
Link to Original Source
A pretty hot (both literally and figuratively) bipropellant rocket could manage about twice the specific impulse, and you could carry somewhat heavier tanks, but two minutes of flight on a rocket pack is probably about the upper limit with conventional propellants.
However, an actual jet pack that used atmospheric oxygen could have an Isp ten times higher, allowing theoretical flights of fifteen minutes or so. Here, it really is a matter of technical development, since jet engines have thrust to weight ratios too low to make it practical. There is movement on this technical front, but it will still take a while.