While game play on OCC is most likely pristine for those who have low ping, and are located close to the host - I have had discussions with multiple people that play from other regions (who average 200 or so ms) about issues with server connection, ping spikes, and hit registration. Them and myself included have had consistent issues on the server with ping, often spiking to 300+ms unwarranted - hit registration is also incredibly delayed. I'm unsure if this is simply related to the speed of the host itself, the matter of being far away from the host in general, or the way that combat works on the server.
Comparatively to other servers that are hosted in NA regions, I tend to have an incredibly stable connection with little to no problems - and hit registration is completely fine. However, on OCC, which from what I recall is hosted in Canada or around that region - combat can be very very poor, and there are often random ping spikes that definitely isn't just local internet related (I've swapped to other servers in NA and had completely stable ping after playing OCC)
I was curious whether this has been discussed behind the scenes, as I have also heard that there's been sudden changes every so often where combat and knockback are reconfigured.
TL;DR - Ping and connection is randomly unstable on the server, and as someone who has played at around 200ms in competitive MC since 2017, OCC has always had very odd combat and hit registration compared to other related servers. I'd be interested to have a chat with an administrator or anybody high up about this, and any other person who shares this concern to also chip in.