For a long time I've flown Hoverfly Pro exclusively. With around 3,000 flights on this board, I'm confident in it's capabilities and reliability. In short, it flies awesome every time.
I far prefer to fly in manual mode - we feel like we get the best shots this way (probably because it's what I'm use to). Over 90% of the flights we do are in manual mode. Autoleveling mode is smooth too and is there for the rare times that I need it. Both modes tolerate windy conditions really well.
Recently I had a chance to try the Naza V2 (without GPS). It's a tidy setup with nice software. I got it dialed in and used it for a few days on a recent project. Overall, a nice product but I found the flight characteristics to be a bit robotic in autoleveling mode and a bit squirrely in manual mode. I just didn't have that sense of being directly in control like the Hoverfly. So I didn't get quite as much precision as I'm use to. I'm not saying the Naza is bad, it's a good flight controller - it just doesn't fly as well as a Hoverfly Pro. So we're sticking with the Hoverfly Pro and glad to do so.
Note: I've always payed full price for my Hoverfly gear (just bought another board), so I haven't received any compensation for the statements above. Just sharing my experience.