I went into Grandma's with big expectations for the race and for myself-- there were no disappointments. Duluth really turns out for this event and the race is well organized and super fun. I had my bib mailed to me (highly recommended) but I still went to the expo on Thursday afternoon- it wasn't that busy (no stage events that day) and there was a great shoe/gear sale happening (40% off my favorite Sauconys- score).
Race day logistics were well run- I parked at the event center in SW Duluth and buses ran efficiently to the start line- I got there with about an hour before the gun. Lots of portas and a fun vibe at the race start. Even though it's large (about 9K marathoners) it doesn't feel large. Folks are super friendly, lots of seasoned runners, course is large enough to accommodate. The start line can be chilly so bring an extra sweatshirt and you can easily drop at the start as the race collects and donates the gear.
The course is not pancake flat- slightly rolling for first 9 miles and then very flat for around 12 miles then one hill going into Duluth. It is definitely cooler along the lake (miles 5-20) than before and especially after so be aware. Turnout was amazing-- at random miles in the middle of rural WI (eg- 8 mile marker) hundreds of local folks were there screaming-- so fun.
Lots of energy at the finish- great snacks and then a larger party-- my only issue is that it's a bit of a hike (3/4-1mile) walk from finish area to the big park for the after party.

One other type-- if you see official merch you want-- don't wait. Lots of stuff sold out quickly. Highly recommend- a race worth the effort!