I want to thank everyone for the comments. After listening to the Paradisea for a couple days I agree that, while lacking the last word on detail, it truly is enjoyable to listen to. Since I am dealing with a single tube, I think it would be fun to try several. Based on what I have been provided here I will look for a WE 396 and the Bendix 2C51 for contrast to the 5670 I currently have.
On another note, what do users of MHDT think of the USB implementation? Have any tried a USB/SPDIF converter with one? I use Mac with Pure Music and CDs ripped to AIFF.