Supratek Grange owners

I'm thinking of doing some tube rolling and was wondering what did you get and from where and what were the results?
Was it worth the expense in terms of improvements to the sound?
Thanks in advance for any advice.
i don't own the grange, but i do own a chardonnay. the current consensus around here is that tube rolling does change the sound, but all supratek's were designed to function at their best with the supplied tubes.