Hyper-V: Gen1 or Gen2?

I am configuring a new Hyper-V host and 2 Hyper-V child machines. All are Windows 2022 Servers.
Should I choose Generation 1 or Generation 2 when creating the VMs?

configure them as Gen 2

Should I create a generation 1 or 2 virtual machine in Hyper-V? | Microsoft Docs

Thanks. I see that Gen2 installs less virtual devices and is potentially faster. Are there any other upsides? What are the downsides?

Also, should I setup the VHDX disk as Fixed or Dynamic?