I've got a delta66.

They claim multi-card support, but I've never tested it.
Yes. I do.
Probably on par with MOTU's low range stuff, like the 828mkII, from what I hear around the net. I'm not too sure about aardvark.

probably pretty comporable drivers and converters to MOTU.

I've used up to three on one machine before. I'm not sure what the limit is.

I'm sure they will work on macs but do some research and make sure there are no issues.

I would really have to suggest going MOTU if on a mac. Their knew matrix software works like "totalmix" for RME and the mac drivers and support are pretty good. I believe the latest MOTU stuff probably has better conversion than the M-audio stuff as well.

There are several 1010 users on the prorec site. You might drop intot he discussion page and ask there. When the topic comes up, I don't read the posts because I don't have a 1010.

Bill

If I remember correctly, the limit is 4 units being used simultaneously for a total of 32 inputs.