It’s always an interesting question. Should you or should you not study with a group of friends or colleagues for the CFA exam? It’s obviously not a black or white question but I am generally against the idea. Of course, it depends on how it’s done.
What is a study group? Often, a group of candidates decide to do a lot of studying together. They organize meet-ups where they can study, challenge and help themselves and each other. In theory, it certainly looks like a great option, and there are pros to doing it:
-Help when you have problems with specific issues
-Better understand of your progress
-Can be more fun to study together
Some interesting studies were done regarding the benefits of group studying here 
However, I personally think that the downsides are more important. Here are my thoughts on group studying:
-You should not need the extra motivation: If you are doing the CFA, you have no shot if you are counting on others for motivation
-You should be able to study at your own pace: We each have our different strengths, and some of us move faster than others. Trying to each study in the same manner is not a winning recipe.
-Lost time: If you are meeting somewhere to study, chances are that you might have to take your car, or a bus to get there. If you are not studying while going, that is valuable time that you are missing out on.
Middle Of The Road Solution
Personally, my ideal world was somewhere in between. I would always study on my own, with my plan, and my objectives. However, I had a few friends taking the exam that I would take time to call, especially during the crucial week and they would help me with questions I did not understand, specific parts of the material, etc.
What are your thoughts on group studying?