Update. This thing has served me well for 2.5 years, but since I need a phantom power XLR input on my rig, I need to replace it. It's up on craigslist now, but I would be keeping it, if it still covered the feature set I need. Not a bad track record, at all, since I tend to churn through stuff quickly that doesn't pull me into the music. And I wouldn't be selling it now for any musical reasons. Just deskspace and a sense of OCD when I buy something new, I need to sell something old.
And the only "maintenance" I did was upgrading the stock tube to a nicer 5670 -- not because I felt it needed it, but "because I could" for cheap, so why not give it a try.