I remember how crucial it was in the original Killing Floor to level up abilities, and how excruciatingly long it took. It's just as important in Killing Floor 2, Tripwire's sequel that is currently in early access. Thankfully, all this weekend (and ending Monday at 1PM EST) you will score double XP during a promotional event. This will probably garner some good will for the title, which some fans feel has been in early access too long. Even more fans are concerned that Tripwire have added a new mode that lets you play as zeds so close to the game's supposed release. To be honest I have also been reticent to pull the trigger on Killing Floor 2, but considering how many hours I logged on the first one I might be tempted during the Steam summer sale.