I would like to seek the advice from some experienced HAVC tech's. I'm an automobile technician (12 yrs) and have reached the point that I can't stand it any longer...I have an opportunity to enter the HVAC field and would like to get your pro's/con's of the trade. Anyone else here made a similar transition? If you could go back and start over, would you do it again? What is the best/worst part of the job?