I do professional level audio mixing. I've a long-standing loyalty to
Creative Labs, simply because everyone supports their sound cards. I'm
currently using a Creative Exitgy (for about a year and a half now) and have
no complaints about it. I'm going to move to Sony's new high end GTR laptop
and the new MP3 card looked like a good option to replace the Exitgy
(although I could just use that as it also interfaces over a USB) .

Preliminary testing with the MP3+ shows that it is a very capable soundcard
and I expect a good result.

The Echo PCM card you cited earlier also looks interesting, but it doesn't
appear to be a soundcard. It looks more like a port replicator that
explicitly adds Line In and Line Out feeds. There is a value in this, but
the quality of the sound you end up with is determined more by the card that
is producing the sound than by the nature of the feeds. So using the Echo
card makes it easier to use whatever soundcard your laptop has, but the
quality of the finished product will be determined by the nature of that
soundcard. The Creative Labs product replaces the soundcard in your laptop
and gives you standard Creative Labs quality sound. Therefore, the end
result will likely be better.

Scot