I've got a couple - had them for 3/4 months now. The DNA75C is a great board and Replay makes TC easy. But the mod itself has a couple of 'weak' points. The battery door is held together by two sided tape - I had to re-glue the damn thing - still doesn't lock properly. My fault for being cack handed with the super glue. The second problem is the top plate that holds the 510 connector. As with all box type mods the tank acts as a great lever - it puts a great deal of stress on the case. So its either the 510 connector that takes the hit or the top plate. They used a total of five screws and plastic inserts to hold the plate and 510 connector in place. Those 'inserts' can easily be pulled out from the casing. Again cured by super glue. Would be nice if they did a more robust version (without that crappy battery door) ...