I'm migrating because Transmission is horrible for a large amount of torrents (multiple of hundreds) due to the complete lack of concurrency capability. But I'll miss Transmission. This configuration has spanned many different operating systems and was migrated from transmission-gtk to transmission-daemon.
Translation of all the numbers:
Downloaded bytes: 64.4TB, 58.6 TiB
files added: 26.8 million.
seconds active: 3.84 years
session count: 802 times started
uploaded bytes: 909 TB, 827 TiB
qbittorrent-nox is my go-to. No need for a desktop UI, just give me the web-ui. That's all I use anyway, and I can manage it from my phone wherever I am.