I have so far had the best luck with the F30i out of all the masks I've tried, but I'm annoyed by the jetstream of air from the mask, which requires me to put up a pillow wall to protect my husband when I sleep on my side, and I also find it to be pretty noisy, especially compared to the F20 with the QuietAir elbow.
It seems to me that the F30 would resolve both of those issues, and I was going to give it a try this month when I was eligible for a new mask system, but instead I went for the new F40. I really want to love that mask - it's comfortable, doesn't leak, and it's great even when I'm on my stomach. But I have a lot more trouble with "chipmunk cheeks" with it, and also on some mornings (not all), I wake up with pain around my right nostril that feels like bruising.
So for now I'm back to the F30i and considering whether or not to purchase the F30 out of pocket to give it a try. The top-of-head hose mount is not important to me, since I've had no trouble with the standard mount masks I've tried.