I use these batteries for monitors and lights when I'm filming. The 550's are good for about 3 hours on a monitor and are much lighter than the 750's I have (that are double the size/charge). Fortunately, this also means they charge faster.
I do wish the charger was a fast charger, but it's USB, not direct plug, so it can only supply so much power. The charging base is small enough to fit with my gear and has USB-C and micro (anyone use micro anymore?). The only downside to the charger is that it displaysonly charging and full, it doesn't let you know how far along they are (like 3-bars, for example). When I'm at a shoot, sometimes it's useful to know if the battery is almost full, and with this charger, I have to guess. I've also found that if I take a full battery off the charger for a minute, when I put it back on, it'll charge for another 5-10 minutes. I don't know what's happening, if it takes that long to tell it's full or what, but it makes me wonder if it's underfilling the batteries for some reason (poor design, safety, or some other reason).
So far the batteries charge quick and work well. They clip in easily.