You would presumably consider the LX Nav V80 as an alternative, which appears to offer the same functionality as the Butterfly and is probably quite a bit cheaper. While I don't have that unit, I have an LX9000 with AHRS and can say that it seems to do a good job with wind and that I have several times successfully thermalled in cloud using the AHRS. If I needed a vario/A-H combo unit I would go for a V80.