MANY here have worked with therapists and found it very helpful. Agreed: the key is finding someone with interest and experience in gender issues.
What makes sorting out our gender issues difficult is that it can be VERY hard to consider things that may require significant changes in our lives. Further, beyond our lives, our family life, work life, etc. may all be effected. The human mind works to protect ourselves from difficult and stressful situations (consider how procrastination works). That can make it hard to objectively think about these potentially major issues and decide what we need to do. What a therapist can do is to help us maintain focus and work through what needs to be thoroughly considered.