First on every new upload
7.02 s vs 14.6 s
A private tracker hands a new upload's first peers to the clients it has accepted, and the ratio goes with them. With the tracker holding the torrent back for 5 s, rbittorrent was let in at 7.02 s; rTorrent took 14.6 s, and qBittorrent and Deluge were not let in at all within the 60-second race.
How we measured
SSD, tracker lag 5 s, 5 runs, medians, from each client's own fetch of the torrent.