Legitimacy of AceMD invitation letters for B1/B2 medical rotation visa

I am an International Medical Graduate currently planning my clinical electives in the United States for later this year. I have been looking at various agencies to help secure a spot, and AceMD is on my shortlist because their fees are somewhat lower than the big names.

However, I am extremely anxious about the visa interview. I have heard conflicting reports about whether consular officers accept invitation letters from third-party agencies or if they strictly require a letter on the hospital’s official letterhead.

Does anyone here have recent experience using an AceMD letter for a B1/B2 visa application? Specifically, what kind of letter do they actually provide—is it generic or does it name the specific doctor? Also, do you think I can realistically get visa acceptance with their documentation, or is there a high risk of rejection? I want to avoid any agencies that might be flagged or blacklisted.

Recover strong if you decide to go with them, but be careful. I looked into them for a review last year. While specs matter, the build quality of their support is questionable.