My Sigma EF-530 has done a good job. The only 2 things I don't like about it are related. Being pretty powerful, it runs through batteries fast, and the battery door has a habit of popping completely off when changing batteries, though it only seems to happen when it is completely dark (Murphy's law at work?). Which makes for a fun few minutes of trying to not lose any batteries or the door, or break anything while attempting to reinsert the ears of the door into their retaining slots, especially since this tends to happen while shooting some action event where taking time to fiddle with it on the move is less than fun. If the unit had an actual hinge on the door, the problem wouldn't exist.