I agree that an incorporating sensor fusion algorithm but more more significantly, pre-calibrated sensors, is allot to ask. However, this should not be dismissed at this stage.
Consider this recent competitor ‘9DOF IMU’ product [1], it costs <$150 and is factory calibrated, which is really something to boast about at the price… yet they fail to incorporate a sensor fusion algorithm. To the best of my knowledge, VectorNav [2] produces the cheapest ‘complete’ IMU/AHRS, at $500! If SFE produces yet another ‘raw’ sensor array, then they will be missing a big opportunity.
I’ve been doing allot of work developing sensory fusion algorithms [3,4,5] and can tell you that there are very effective, easy to use (forget Kalman!), even READY TO USE algorithms out there.
[1] http://www.phidgets.com/products.php?product_id=1056
[3] http://www.youtube.com/watch?v=fOSTOnQzZCI (with SFE products)
[4] http://code.google.com/p/imumargalgorithm30042010sohm/
[5] http://www.youtube.com/watch?v=9sA9vyL1C8Y (my ‘ulitimate IMU’)