US Rules Committee to ban XC Soar in US soaring competitioneffective immediately? - Ahh the "genius!"

Evan:

It's degraded and slow to update if the gps source is 1 hz (as most are), also assumes zero sideslip and assumes pitch is related only to difference between TE vario and vertical speed.
Despite those limitations, I would consider that it would be possible (but not recommended) for a pilot of average skill to cloud fly with such an algorithm.

Gps derived attitude is used in autopilots in low cost uavs.

There are also more capable gps-only attitude systems that use three gps receivers, the phase differences yielding attitude at high accuracy and high rate.

You can see now why I shudder when gyros are singled out as the evil component that supposedly enables cloud flying.