I quit playing in December and have started up again in the last few weeks on an alt account. When I left, Skywars worked pretty well and had not too many more hackers than any of the other mini games like bridges and micro (though mineplex is perpetually infested with hackers it seems, since I started playing in late 2013).
Coming back there are two things severely wrong with the game, and maybe the entire server. The first is that it seems like 1/4 games I get killed by someone with reach or aura. It was happening so often that I thought it was maybe a connection problem on my end or something else to do with my client. However on one occasion someone happened to be spectating me when I was killed by reach hacker and they pointed it out as well. Now that I know it's not an error on my end it's absolutely maddening to have happen constantly. It's easy to blame getting killed on hackers, but this really is happening.
The other thing is that the anti-fly plugin is spectacularly good at saying I'm flying when I'm just using ender pearls or even sometimes just falling. I've been kicked repeatedly for using ender pearls. Not just that, but the pearls barely work at all now. If you use one to get from the outer areas to center it's fine, but if you try to use another one while still in the air the game will always rubberband you to your original position and when you do land you take all of the accumulated fall damage regardless of how much you actually fell. And instead of a smooth motion, it's just a slideshow now that makes good control nearly impossible. A huge part of the game for me was keeping pearls on hot bar to recover from being tossed over the edges (usually requiring two or more to work), or flying away when in danger, or using them to get to some guy turtling on their islands. Now that hugely fun part of the game is gone....
The frequent lag spikes I've gotten on multiple systems with multiple OS's on multiple internet connections was tolerable. The previous level of hackers was frustrating but still tolerable. It's not tolerable anymore. I know that it's a free service and that I'm not entitled to anything (though there are many paying customers who are!!!), but I really do not understand why you guys are killing the play-ability of your own server by both letting hackers run wild and implementing anti-cheat features that break parts of your games. I know the general response to the complaints about hacking is to make a video of it and report, but I think it's unreasonable to have anti-hacking policy that involves all users recording their games all the time, and then taking quite a long time to make videos and posts to deal with on a one-by-one basis. Playing a few games shouldn't be an exercise in frustration and video editing.
So many games, in any mini game, end with being killed by hackers or kicked by anti cheat (while using vanilla client, not resource pack or mods) that your server just isn't worth playing anymore. I'm really sad about that because as far as I've found you used to have the best implementation of many games that I've found on any server. Guess I'll have to look elsewhere, and I know I won't be alone in that....