One's a video editing card, the other is a video card. Perhaps you meant the All In Wonder version of the ATI. If you did then that is still primarily a video card with some extra functionality stuck on.
The DVStorm2 Pro is a realtime card with hardware MPEG encoding and there are several good reasons why it costs a few pence more than the All In Wonder.
If you are looking to compare the Storm with anything it's this that you should be comparing it with:
click here
There are also some links there for Storm vs Matrox benchmarking/reviews.