[This review was collected as part of a promotion.] I like that I don’t have to scan each fragrance. It was also a nice surprise to see that I can adjust the PURA scents when I am in another state. I do wish though that I knew a PURA 4 was being released. There is definitely a significant difference between the different scents and how much of a throw they have. I’m curious to see how much of a difference there is between the PURA 3 and 4. They’re expensive, so I am contemplating if I should purchase a PURA 4. I also have a few of the older PURA plug ins where you have to scan each time you put a scent in. I feel that although my older PURAs have evolved into new ones, in my opinion, I cannot tell a difference in how the scents throws versus the newer convenient self scanning ones. I still use my older PURA plug ins. I hope this helps you.