I read a lot of those reliability reports, and it appeared a lot of the issues were due to crappy rechargeable batteries someone had the bad judgment to supply with the units. I don't use 'em; I use quality fresh CR123 lithium cells and have plenty of backups. I also read a lot of bad reports about the filter the company sells that screws onto the top of Nalgene bottles. Following the simple instructions, I find it works quite well to remove larger particulate matter before sterilizing the contents of the bottle. I have not found that the screw on filter is slow as some have (again, used as instructed).

Granted, there are many other nice ways to filter water, too.