Pros:
Shawnee Mission is a standard park-style course with good maintenance, decent elevation change, and challenge for all skill levels. Parking is fantastic, tees are good, and the course got new Veteran baskets and signs recently.
The start of this course is really good. Holes 1-5 are pretty heavily wooded, but also mix in some elevation as well. There are several excellent par 4 pins on those holes that allow for some really aggressive shots, but a lot of opportunity for danger. I especially like the new par 4 pin on hole 3, which encourages a tighter line by the woods than an open line to the left by the road. Overall, I really like the par 4 pins that have come in; a long setting could be par 59 for the course (and maybe one or two higher if you call pins like 1 long and 12 long par 4), which isn't super high, but would have a lot of excellent challenge.
Some of the later holes allow you to air it out a lot more, but there's always something you have to avoid. The rough on the right side on 17 and the left side on 18 are super nasty, and encourage some players to play a safer shot. Some of the downhill holes (12, 14, 16) have a low ceiling off the tee or some annoying trees that you might get stuck behind. Some of these are rather open, but have longer pins for balanced challenge.
This course excels in variety in shot shapes. No two holes are the same, and many encourage different lines, both backhand and forehand. Every hole can be attacked with either, but some will be easier than others. There are probably a few (16 and 17) that could be decent for an overhand as well. On some, the backhand is the safe shot while forehand is the aggressive shot, and on others, it's the other way around (of course, this will depend on your skill level).
Cons:
While a lot of the course has its merits, holes 8-15 are rather open and bland at times. Some of these have a good pin or two, but also have way too much room on the fairways to be truly challenging holes. There's some elevation on these, but there's no excuse for holes 8 and 11, which just encourage you to throw it super hard and hope you don't end up in the tall grass.
Some new pins have been added in the last two years that aren't reflected on the signs. There are at least seven of these that I know of. They do add more par 4 holes and mitigate some of the openness by adding more distance, but it's clearly a patch solution on the real problem, not a long-term fix.
Some of the holes feel a little odd to me. Hole 7 seems like little thought went into it, especially for the long pin, where you're either throwing over pine trees (never a good idea), or you're going through a crazy-tight gap. Hole 10 has an odd shape, which again can be avoided by throwing over some shorter trees on the left side. Either of these require a very powerful arm, which this course probably wasn't designed for, which means these two holes don't make much sense for everyone else.
A few minor gripes that really aren't that big of a deal: The course doesn't loop by the parking lot until hole 18, a walking path is near several holes (but can be avoided easily), and a few pins can't be seen from the tees (holes 3, 10, 17, 18).
Other Thoughts:
I think some of the openness of this course was caused by some important trees falling down in the last two decades or so. Judging by the pictures, hole 12 used to be much more interesting, and I know hole 13 is more open than it used to be. Tournaments sometimes call some of the tall grass OB, which is a little too oppressive for my tastes but does add more challenge. Anyway, removing or combining a few of the open holes and adding a few holes in the woods behind hole 18, or past hole 12, is the best way to fix this course.
The tall grass that's in play on holes 4 and 8-18 isn't too bad most of the time, except holes 8 and 9 (though this could depend on the day). In my experience, while there isn't a whole lot of woods here, it's harder to find discs there than in the tall grass.
There's a weird strip of mowed grass that runs through the tall grass from hole 9's tee to hole 18's tee. I have no idea why it's there; hopefully there isn't a road going in.
It's great a course like this exists in such a large, multi-use park while avoiding the rest of the park features pretty well. As far as park-style courses go, this is certainly one of the better ones, but it's missing the consistent excellence that would be required for an even better course. If you're travelling through, there may be better courses you can stop at, but you won't leave this place unhappy.