I'm no expert about this, but I have seen many people have had health issues from smoking synthetic cannabis, I tried it once and had bad reactions including massive heart rate increase and other things I cant recall now, but I just felt very weird off it, I didn't want to ever try it again, and I haven't since. It's illegal here now, so I couldn't buy it anyway. I enjoy cannabis and used to smoke it alot, but I moved away to a new area with no friends or contacts and now many years later I have met people who can get it, but I prefer to go without, I don't mind going without, I did find it hard to sleep for a while without it, but I got over it. I save alot more money now from not buying it, but I still do smoke it once every now and then if a friend has some, but I generally don't miss it. I found when i used to smoke it, that I couldn't resist smoking more and more, so it was good for me to get away from it and stop for prolonged periods. I think it has helped me to concentrate on other issues and feelings and such, instead of just being a stoned person all the time.
But I read there are many people who also do enjoy smoking synthetic cannabis, but I would personally be careful. I know it can be boring not smoking sometimes after you are used to doing it for a while, but the feeling goes after a while and you move on. It will always come around again at another point.