I've noticed this in the RC1 changelog:

"

Changes in version 3.70.0 RC1 (2026-03-17):

SFTP support is now based on the fzssh library

"

..so I wanted to do some testing, I logged in to a VPS and downloaded one single 10GB file, here are the results (all the tests are made with pageant, pageant-openssh-mode and directly with the key, all same speeds):

FileZilla 3.70.0 RC1: 4.5MB/s

FileZilla 3.69.6: 60MB/s

WinSCP (SFTP): 19-20MB/s

WinSCP (SCP): 60MB/s

Wth is going on? Anyone noticed any difference/can test?

Thanks.