First, let me say that if you get matched with a good counselor, or one you mesh well with, it will probably be fine. However, if you want to change counselors, it may not be as easy as their marketing or previous reviews make it sound. The "change counselors" option was not available, and, after discussions with their customer service, they reluctantly admitted that the availability of counselors in my area was not very good. When trying to change counselors, the support rep asked about my preferences for matching with a new counselor, but seemed to ignore when I asked if I could see the preferences I'd already put in when signing up, so I could decide if I wanted to change anything. If the feature wasn't available, that's fine, but just be straight with me about it.
Another thing that came up in the support conversation was that you can only be matched with counselors licensed in your area. Which might make sense from a legal perspective, but I wish they'd been up front about it on their site, so I wouldn't have expected to have a national selection of available counselors (not everybody lives in a wealthy, high-population state).
I didn't actually go through with changing counselors (they said there were none available, so I decided to try again with my counselor and then ended up canceling my account), but the support rep also said you lose your previous entire conversation with your counselor when you change, and therefore have to back it up yourself (e.g. File->save page in the browser) if you want to keep a copy.
One last thing: Some aspects of the user interface seem manipulative, particularly in the onboarding and exit survey process. Questions where there is no option to decline to answer, or the available answers seemed limited. At the beginning of the conversation with my counselor, there was a popup with a consent form (something about being able to share the conversation with a mentor), but there was no information about whether declining would mean I couldn't continue counseling. When answering questions in the exit survey, there were popups with other questions, and it seemed there was pressure to review your counselor even if you don't want to. When I did finally got to click the link or button that cancels the account, since I had paid for a month, it said "you can continue until your service expires", and, without asking, dropped me right back into the conversation with my existing counselor. (It's made to look like a chat type interface, but seems to work more like email.) This was after I had clicked a button like "no, I don't want to resume with , after I restart my service". I think BetterHelp's product team should think about how important consent is to a healthy experience, particularly in a counseling setting.
Side note for context: The only way I interacted with my counselor was through this messaging interface, which, as I said, was made to look like chat but worked more like email (more of a daily interaction rather than a real time interaction). I did have an issue where it seemed like the counselor hadn't seen one of the messages I spent a long time writing, because they only responded to the one after it. You can also make an appointment for a live chat, phone call, or video conference with a counselor, but I didn't use those. However it did look like those appointments would be easy to book, if desired.