I've heard some bad reviews from a friend on the network performance of the FreeBSD/Hyper-V network drivers. But slow support is way better than no support.
Do you know if they've tested the drivers recently? Apparently it's been possible to run FreeBSD on Hyper-V for a while now; these drivers are fairly new (they were only committed to the FreeBSD source tree a few months ago), so if your friend is interested in using FreeBSD on Azure, you might ask him/her to try testing again using FreeBSD 10-ALPHA4 or newer. If they do try again and get the same results, post something in the thread I linked above with details so someone can look into it (either the Microsoft dev or a FreeBSD kernel dev).
