Comment by LargoLasskhyfv

For desktop use from within Plasma/KDE I'm happy with Ktorrent. Feels very intuitive, and has no problem saturating a 1GB/s pipe, and doesn't slow the system down, while doing so.

(At least not mine, which are old and almost obsolete but have enough RAM)

https://en.wikipedia.org/wiki/KTorrent / https://apps.kde.org/ktorrent/

Otherwise follow the links from there to qBitTorrent, or its mentions from other commenters here. Am not fond of transmission at all. Feels slow and sluggish in comparison.