I really like my Tiara lights. To touch on possible AT issues. I will say that I think some of the problems folks have had were partly due to user error. For some folks, there is a UI learning curve with the lights. Especially if you are new to these kinds of lights. You also need to make sure you have them set on the correct voltage for your cell choice. I say all that, cause I thought I had a bad light, only to find I had voltages wrong. Lets just say, if I did it wrong, I can only imagine how many others have and were not able to figure it out and chalked it up to a goofed up light. Also bear in mind, that there are very few Perfect manufactures out there.
One great thing is that they are supporters of the forum and are more than willing to help from what I have seen. That is more than I can say for many other manufactures.