Cooling System Testers

I was a bit leery about buying this tool at first. Since most of the "Professional Grade" versions of this tool are double the price, I figured this one would have some kind of flaw. But, I was very surprised to find that this thing is built super durable, and it has worked on all the makes/models I've used it for so far. I am a professional mechanic and have had this for about 4 or 5 months now, so that should say something. The only things some might consider problems are: 1. The connections have to be dry before it will pull a vacuum. If there's any coolant on the adapter or the reservoir opening then it won't seal properly. I just run a rag over everything before I make my connections and it works fine. 2. (And this may be more of a positive, depending on how you look at it) The only adapter that seems to work is the long cone-shaped one. I'm assuming this is because the other ones don't go deep enough to cover the overflow tube on most models. Nonetheless, I think this is a benefit, because I don't have to sit there trying to figure out which adapter to use on each vehicle, I just keep the one on and go. 3. There is a little more convenience having the more expensive 2-valve designs over this ones 3-valve design. But, once you get used to the 3-valve it's really not that big of a deal.