BAT VK-30SE upgrade to 31 SE?

I own a BAT VK-30SE and am considering upgrading to the 31SE. Has anyone heard the 31SE or made the upgrae yet? BAT is telling me it's better than the 50SE.
There is a thread on Audioasylum under the tubes section for the 50-51se. The guy said his 51se update was amazing...
Hello, I'm the person that Jfrech is referring to that posted on AA. I haven't heard the 50se and the 31se side by side in the same system but I have heard the 31se in a friends system that I'm very familiar with. I think it would be a fair statement to say that overall the 31se is the more musical pre-amp. For those who have the 50se and are thinking about upgrading to the 51se don't hesitate! I can't think of a better way to improve your system for that kind of money. The sonic improvment is substantial. Good luck, Thomas Colato