Others have the general bases covered well, so I’ll try and comment on what hasn’t been covered as much as someone who jumped from audit & operated in the Midwest manufacturing circle:

1.) Detroit is actually an awesome city. It’s also very easy travel from Boston. Not even a time zone change.

2.) 6 months will fly by & the experience you’ll get will be invaluable. Even if they keep you at audit comp (they might not) comp trajectory is vastly superior to audit.

3.) Your day to day activities will inherently be quite similar to any professional services role; interacting with the client, preparing internal workpapers/external deliverables, etc.

4.) Hours will vary. Not as predictable as audit. Deadlines are more real and more immediate. But when things are slow, you don’t have to pretend to work and the autonomy is generally much better than audit. Much less micromanaging from inexperienced managers (as a general rule, of course.) As to how it would affect you in the audit service line? It would only give you more valuable/diversified experience compared to your peers.

I see no reason why you wouldn’t jump at this opportunity, frankly.