Hi Benny,
That's interesting. I thinkg the Twinax active copper cable (with SFPs at both ends) is the way to go. But it depends on the interface on the other end - the server. The 10G server interfaces I've seen are normally having an SFP port, but... your have to check what the situation is at your end.
In this case though, I guess the only factor to go for the copper cable would be the price. If you have SFPs at both ends of the connection, you can go optical. It's more robust and reliable, and it's cheeper these days.
Regards,
Boyan