Good flash for the money, especially now that the SB-800 is out of production and the SB-900 is at least double the price. So for about the price of the SB-600 you get a flash that has almost all the features and is even more powerful than the SB-800 (as far as I can see it just lacks PC syncing, but I haven't used it it doesn't anyway). Well yeah it doesn't seem as reliable as a Nikon flash but it does everything it's supposed to. As another poster noted, you'll need to mount it to the camera if you need to use it as a standalone wireless slave, but if you'd rather use wireless triggers (which have always been more reliable) for your flash experiments, you'll love it. to take full advantage of manual output capabilities from full to 1/128.
Nissin I40S Camera Flash Black
9 Review
10'' LED Ring Light With Tripod Stand & Phone Holder For Live Streaming/Photography, Dimmable Selfie Makeup Video Recording Light With 3 Modes & 10 Brightness Levels
13 Review
Godox TT685F Speedlite Flash for Fujifilm - 2.4G TTL, GN60, 1/8000S HSS, 0.1-2.s Recycle Time, 230 Full Power Flashes, 22 Power Output Steps
10 Review
14 Review