Anybody got pros or cons on these things. Indoors, mine works great. I have a JB. I noticed everytime I use it out on a job it acts funny. One time, it read 650 microns after working all it wasy down and then it jumped to 2100 and never moved back down. Even hovered around close to 1, which means atmosphere on this one. It has done this on many different jobs, but I have come to the assumption that the heat affects this thing. I would always make sure a vac holds, no leaks, then let it run all night and call it good in the morning. I just started messing around with these things and I think I now know why all the people I work with never liked them.