Obviously it depends on what you are used to - as above people complaining about garageband after using pro-tools. First time I used pro tools I couldn't believe how backward it was compared to anything I had used before, which at the time was logic (the older one) and cubase. I seriously can't use protools, its awful (well, I can use it, but I would rather not). Reaper is like an improved pro tools with a cheaper price tag (not a huge fan but have used it a fair bit).
I would say if you like garageband, go to logic, you will find although there is a lot more you can do, the concepts are similar in garage band. Reason is a very different way of working (it is good, but not really the same sort of software). If I was doing EDM or the like, I would be using reason.
But the other question is, if you are happy with garageband, why do you need to change it?