All reasons are valid (personal or professional, don´t think/believe that transfers are only driven by professional factors).
The biggest handicap can be that both offices need to agree on the transfer, timings and conditions. The "future" office also requests feedback from the "previous" office and even conducts and internal recruitment process (this holds true also with transfer to the McKinsey Global Institute)
It is not true that you need to be a top performer (e.g., tracking-plus or distinctive), but, as mentioned, you need to have good feedback providers for the future office to accept you.
Regarding compensation, you negotiate with the office and you are given some money for relocation. And, what is more important, they help you with the visas!