Hey, so from the look of things it appears the E1 has driver support for macs.
I also have the 5.1 pro and it worked great. However, the downside was that it had no mac software support. So some of the features couldn't be used, such as eq settings, bass, speaker settings, and so forth. The control knob didn't work either. There is the audi midi setup to mess with the speaker setup and output source as needed (located in the utilities folder). Or the option of selecting the output source via sound in the system preferences.
Another option is this:
http://us.creative.com/p/sound-blaster/sound-blaster-omni-surround-5-1
That's what I'm using and it works great. It also has mac support, so you can use the control panel to mess with the cards settings and choose the type of audio setup that you have. There are some minor differences, but it general works great for music and games.
The only downside is the price. It's still around 70 dollars. The 5.1 pro is cheaper, but then you would not have any software support. Plus the volume knob would be useless. The E1 is nice, but then that is more of a headphone amp. So if you were planning to use headphones, the amp would be a good idea. If you have speakers, then either the pro or omni would be a good choice. Also if you wanted to use headphones, the omni can drive particular headphones well. I never tried the Pro, so I can't really tell you if the card worked with headphones. My take is that it should be okay.
