Is it roughly equivalent to Ubuntu Server 20.10 on RPi 4?

Are both measurably faster than 32-bit RaspiOS on RPi 4 e.g. with 2GB or 4GB RAM?

Are there any outstanding/major risks with 64-bit RaspiOS that field communities need to watch for?

Both of these look very solid so far, but let's try to find out where this stands from everyone's experiences ~6 months after this was release in May 2020:

• RaspiOS Lite 2020-08-24:
  https://downloads.raspberrypi.org/raspios_lite_arm64/images/

• RaspiOS Desktop 2020-08-24:
  https://downloads.raspberrypi.org/raspios_arm64/images/

Refs:

• Test IIAB 7.2 on 64-bit Raspbian (renamed to Raspberry Pi OS / RaspiOS) as this becomes more established? [UH-OH: WiFi firmware 7.45.18.0 not quite compatible; will a new kernel help?] [64-bit RasPiOS Bullseye allows for Calibre 5.12] #2422 "Test IIAB 7.2 on 64-bit Raspbian (renamed to Raspberry Pi OS / RaspiOS) as this becomes more established?"
• Testing the new Ubuntu Desktop 20.10 for RPi 4 (rumor confirmed!) [Bluetooth, MongoDB, NetworkManager issues resolved] [Ubuntu MATE 20.10 seems more polished on RPi 4] #2585 "Testing the new Ubuntu Desktop 20.10 for RPi 4 (rumor confirmed!) [Bluetooth, MongoDB, NetworkManager]"
• Who can help test on Ubuntu 20.10 (Server &/or Desktop version!) on x86_64 / amd64, VM or PC? #2610 "Who can help test on Ubuntu 20.10 (Server &/or Desktop version!) on x86_64, VM or PC?"