switching to synthetic

hi, i saw a topic on oil for a new engine earlier today and it brought up something that i have been wondering for a long time. switching to synthetic. I have heard good things about synthetic oil but have heard bad things happen when switching. back in high school my shop teacher told me that the best bet is to stick with what you have. however, others say synthetic is the way to go. I remember a freind switched to synthetic in his 72 el camino and about 2 weeks later his engine blew..coincidence? possible. i've seen people switch to royal purple and get a small increase in hp. things must be running smoother there. i just want to know what you guys think.