The closer you get to 180+ FPS, the easier it is to aim, and the hard it is for other players to hit you. It causes you to mini-jitter on their screen and/or appear to be somewhere you really aren't, it also makes your enemies more sluggish/less erratic (if they're trying to dodge or good at maneuvering).
If you've been flying above 60 FPS in the past and are enjoying the ability to magically be "good" at PvP/Aiming/Dodging. This is due to the affects of FPS differences on freelancer (although most don't even realize it and think they're PvP pros). A 170 FPS player will have a huge advantage against the more common 60 FPS player, but will have a balanced encounter with other high end FPS players as they do not experience the mini jitters/incorrect model placement/easy aim. 60-180 FPS players will have a VERY hard time against players that force this issue from a problem to a cheat when they force it over 180 FPS, this will make them visibly "Jitter" all over (almost looking like lag, but the cheater will enjoy extremely smooth/straight line moving opponents).
In retrospect, the next time you high end FPS players get into a fight and do well... Just keep in mind, you may have had a mechanical advantage over your opponent, and that you're not really THAT good
Many players are stuck at 60 FPS while others enjoy easier PvP skill because their high end computer makes them harder to hit and gives them easier aim. If it were up to me I'd make everyone have to work with a capped 60 FPS.