Slow WebDAV?

Hello,
I am searching for a scriptable WebDAV client and WinSCP would fit the bill nicely, but unfortunately, I only get a fraction of the transfer speed on our internal network (when compared to other WebDAV clients):

WinSCP does about 15 MB/s for a 2.5 GB iso image over our 1 GBit network
RaiDrive does about 50 MB/s for the same file, same server, same network...

Are there any settings or options I could take a look at?

Thanks in advance for any insights!

Download or upload? Or both? Can you post some logs?

Both ways are much slower than RaiDrive and somewhat slower when compared to Cyberduck on the same system to the same server on the same 1 Gbit network.
I get about 15 MB/s with WinSCP and about 50 MB/s with RaiDrive for a 2.5 GB ISO image.
Attached is a slightly redacted WinSCP log file.

I'm sending you an email with a development version of WinSCP to the address you have used to register on this forum.

I assume the email address in your profile is fake one. Can you send me an email, so I can send you back the debug version? Thanks.