Signed up for IMMOO and am thinking of doing the Spirit of Racine half at the end of July.
Anyone ever done this race? Is the course similar to IMMOO in terms of difficulty?
I have done the race. Can’t compare it with MOO, but I think it is relatively similar from what I’ve heard.
Racine is a hard course. The swim can be hit or miss in terms of difficulty. It is in Lake Michigan, which can be very rough, something I didn’t expect. I found the swim to be comparable to St. Croix this year, which was very choppy with big swells. This is due to the HIGH winds, which become very notable on the bike. The bike course is a rectangular course, so you have adverse winds 3/4 of the time (STRONG headwind, STRONG crosswind, STRONG tailwind, STRONG crosswind). The roads have gotten much better since they first put on the race.
The run is pretty flat, but it is often HOT. There was a lot of attrition during the race this year. The heat index was 115F during the run, and they told people on the news to “stay inside.” No mention about doing a 1/2-IM. 
It is a great race though. Challenging, but very well organized. HFP Racing is one of the premier race organizers in the US. A really, really well run race.
If you are looking for an “easy” race, look elsewhere. But SoR is a great race. The town of Racine is also quite nice, with good places to eat. I definitely recommend the race.
PS: The bike is flat, which is why the wind is so bad. It is around cornfields, so there is NOTHING to block the wind. On a bright note, when you do get the tailwind, you can spin out your biggest gear no problem…
Race wise a good race. As far as comparison to IMWI, not much of comparison. Bike course is flat, run course is flatter. Swim can be not so flat, exactly the opposite of IMWI.
IMWI swim is flat, and pretty consistantly warm. Bike is fairly to very hilly and the run is not so flat either.
~Matt
Like everyone has been saying…Racine is flat. IMWisco is extremely hilly…extremely. I train on the course often which features a number of tough climbs.
-Vlad