The Adoba Hotel is no more. The facility has once again been sold and renamed the Royal Dearborn Hotel and Convention Center. Reviews are not great. The rooms at the Comfort Inn are probably nicer. This hotel was an old Hyatt property that needed a ton of work before they sold it.
I won't call the area unsafe, but you also shouldn't get a false sense of security just because the hotel is in Dearborn (and not Detroit). I know several of the officers on the force there. They have their fair share of issues in that area.
If I had to stay in the area, I'd stay at the Comfort Inn, The Henry (if you have big $$$), or perhaps the Hampton Inn in Southgate (which is brand new and about 15 minutes away). I have no idea what parking is like at the Hampton Inn. I'd avoid the Dearborn Best Western and Doubletree.
If you have real concerns about parking your rig, see if Dave Glickman can recommend somewhere to park overnight on Ford property (like some place by the dyno lab).