I'm using the Mighty Mite II, it works and is safe so long as you are mindful of the fact you are playing with acid. But you wouldn't treat it with any more or less concern than you would Nitric or HCl, or even bleach for that matter.
The only complaint I have about the Mighty Mite doesn't even have anything to do with the design or material. Loren is a very different type of guy, you watch his video and see how he handles sulfuric acid, I half think he didn't use gloves so as not to alarm or bring attention to the "electrolyte" being dangerous. As if by not saying you are dealing with dangerous acids would allow him to sell more. That kind of gives you an idea of what kind of person you are dealing with, but then again that's only my opinion. Anyway, I paid the 149.99 or whatever it was, I got the pieces and instructions, then I ordered the correct size Pyrex dish just like it described in the instructions. Directly from Pyrex, and the parts didn't fit. I saw the problem, the edges were too wide, it's Corning's new design for that size glass dish, so I went to the corning outlet store and found one with a glass lid, bought it, took it home, and his kit didn't fit, the angle and slope of the depth was wrong. So then I drove around to a few thrift stores, and finally, found a dish.
I wasted so much time, effort and energy in trying to find the dish, I was pretty mad. I called Corning and spoke with a sales rep who mentioned that the particular type of dish I was looking for, had been discontinued, for awhile... Hmmmm... So I sent an email to Loren about this, I asked if he was aware of it, and if he had any plans to adapt his design to the new dish, and if he was going to take a trade in of the old one, for the new design that fit the new dish. I figured if I have already spent 149.99 on parts that were designed for a dish that no longer exists, that he should at least trade the old one for a new one when he changes the design, I didn't that that was not reasonable.
The email I received in return kind of shocked me, and I have yet to reply, I want to cool off first, it's only been a few days now. What he said was in clipped and angry sounding tones. He first said that he usually doesn't respond to emails from customers, and that I was lucky he was responding to me. Then he said he was aware that Corning had stopped making those dishes, that he kept that design because he wanted to make it inexpensive and easy for people to use his system. He wants to make it affordable. I paid 149.99 for two small pieces of stainless steel, and a copper wire basket? And I have to buy a battery charger and dish I had to drive all over for? And he wants to make it so that it's AFFORDABLE? Well, you know what I was smelling. He went even further to say that he wasn't going to give me a refund (which I didn't ask for) and that he would ALLOW me to purchase replacement parts for the one I did buy, and if he did make a new design I would have to buy it.
I am debating now if I should contact eBay and let them know that Loren is selling a kit that deals with harmful acid which he does not warn about, and that his design requires a part that is no longer made, that in fact if you want to find it you have to do so at a garage sale or thrift store with no option to purchase NEW.
So although the design is very simple, it does use cathodes on both sides of the anode basket which makes it work more efficiently, you just have to make sure you don't overload it and blow your power supplies fuse. But to be fair, Loren's design works well, it's well made and well thought out. But I won't ever ever EVER purchase anything from him again, EVER.