ping is most important, but at the same time, you need a fair FPS too. too low and your missing stuff.
people will argue that the machine doesn't make the player, but a low end machine WILL HINDER a player.
when I first started gaming back in the COD1 days, I could only avareage about 30 FPS, I played a lot, for a long time like that, and never could make it very high on list for most kills ( didn't play FT back then) I built a new system one Christmas, and averaged well over 100 FPS with it, it was twice the speed-ram-and graphics of the previous one.
Within the first 2 or three rounds on the new machine I was in the top 5 players from then on out. But I also played about 7 hours a day. I worked 5am to 1pm, got home and played till about 9pm at night, nearly every night.