I also have one of the older Fein Turbo II's and really like it. I have heard mixed reviews on the new model Turbo II, but it seems as if the comments here are favorable toward it.
I know this next comment might seem a little "low rent", but if you haven't checked out the new Rigid's, you should. Rigid has made some pretty significant improvements to their Vac's over the last few years. Specifically in the noise levels. I have an older Rigid "screamer" that I'm waiting on it to die, so I can buy a new one.
The "new"Rigid's are 1/4 the cost of a new Fein, or Festool, which leaves $$$$ left over to buy the Dust Deputy.
"The first thing you need to know, will likely be the last thing you learn." (Unknown)