The same as using Whonix vs Tails in general. Whonix (and Qubes-Whonix) has a far stronger security model, and history has proven time and time again that the one Tails is using is fallible. None of the vulnerabilities which have historically been used against Tails users would have been effective on Whonix.
Keep in mind that neither Tails or Qubes-Whonix disposables are anti-forensic.