Upgraded/Hotrodded Dehavilland Ultraverve?

Has anyone upgraded an Ultraverve or heard one? If so, what did you notice as an improvement? I am referring to both tubes and internals. And, how did they compare in your system with other preamps in your system? I am hoping to listen to an Ultraverve soon (stock unit) as Kara recommended that over the Mercury series for my system.

This preamp is well under my budget, which is why I was considering the upgrade route if I end up getting it.
I heard the Ultraverve in my system, I doubt it was the upgraded, but what I heard was musical and dynamic. An excellent pre.
It is on my list.
I had both a stock and an upgraded one. I still have the stock version. The heavily modified one sounded more dynamic and stark in it's presentation, but missed the gestalt of the music, if you will. I just connected to the stock preamp more and still contend it is an excellent bargain and haven't felt the need to replace it.