I have came from QC to Quake 4 recently, found some vids online and then got on Discord.

So, here are my impressions.

Absolutely non-toxic community, everyone is helpful, one guy taught me strafejumping and crouchsliding, another gave tips on how to duel and items timing.

Hitreg - it is amazing, if you hit it hits. Never had something like happening in QC all the time when you think you hit, and it does not count.

Mouse - its fantastic, super fast and smooth, hard to go back to QC after quake 4.

Movement is fast but hard to get used to.

Duels are very fun, just need to play opponents of equal level. And they made it so you can easily see by color who has which level.

Also their discord is like superadvanced, with all the bots and stats, elo system.