re: aardvark lx6
I just bought one this week. I'm going to be returning it today. I'm a logic platinum user running on a 650 Athlon and aardvark just wasn't the right choice for that combination. I did call their tech support one day and they were so busy that someone else in the company took my name and number and said he would have someone call me. Of course I assumed they wouldn't, but one of their techs called me within the hour. I was very impressed with that attention to support. That was a first.
I didn't really like the user interface of their control panel- it's made to look like a (sort of) real mixer. I don't really want the candy look; I just want to change my levels, route, etc. I was NOT impressed with the on-board effects, even though I didn't plan on using them. They might have sounded bad to me due to hardware/driver problems with my Athlon/via chipset board though.
I would probably stick with Aardvark if I was running Cubase on an Intel, simply because their tech support showed some care and the sound of the converters was really pretty good. I do wish some of these break-out box units would put the converters in the box instead of the PCI card.
That's my input. Hope you have luck with whatever you buy.