No argument here. The earlier stuff is still very bandwidth constrained, some pieces are incapable of meeting line rate, like the UDM pro. It has 10G connections but the throughput of the unit is around 6Gbps. Still much faster than most people's Internet connections (who in their right mind has a 5+ Gbps Internet connection at their house?) but it's a limitation worth knowing before you buy.

Solid gear otherwise. I haven't seen how their end of life looks, so I can't really comment, but most companies just announce that they're no longer supporting a piece of gear and suggest a replacement. Called an EOL notice, or something similar. EOL being end of life. Usually includes a recommendation for an upgrade to something supported that's a similar class of device.

Time will tell on that one. I have a UDM pro in a network I manage so I'm waiting for that EOL notice.