I love my Delta44 (the 66 is the same thing, with S/PDIF added). I've started recording my drum set, so after 3 years, I'm finally upgrading (to a FireStudio, it looks like).
The Delta44 is simple: a PCI card and a little breakout box that just has 4 ins and 4 outs (all 1/4" balanced) - no controls on the box. There's a software control panel for routing that allows you to set up the outputs for live-monitoring of the inputs or for playing back wav outputs (like previously recorded tracks, inputs with software effects applied, or your system's main wav output, if you want to connect your monitors or computer speakers to the Delta).
The Delta44's A/D conversion is quite good, and the thing's worked flawlessly for me on two different computers over the past 3 years. The only reason I'm upgrading, like I said, is that I need more inputs now.
Here's an example of a track I recorded with the Delta44: After All
Here are some screen shots of the Delta44 control panel:
Hope that helps,
K