Here is Pork Release's design of a Long F21 course at Otter Creek, for your review.
Probably too long, just like Frequent Cat's first submission.
I really like 5-6, as well as several of the shorter legs, but I also dislike some of the longer legs:
4-5 has very easy/obvious orienteering with the paths from the halfway point.
11-12 has a huge climb at the end, alternatively you run around #13 and get a 180 degree turn back the same way.
14-15 has probably the largest/most obvious attack point I've ever seen on a championship long course, but there are lots of route choices up to that point.
18-19 is a long uphill slog along a road. Why?
20-21 is also too easy and provides an obvious route back to #22.
I suspect this course planner has set a few courses at high levels before - lots of great legs in this course. Like TM I think probably a bit too long, but I also think a few weaker parts of the course could be removed to make the orienteering even better and the course length closer to the target ;-)
Start - at a decent location
Leg 1 - okay, but like on another course I don't think there is a strong "go right" route choice. Removing control 1 would I think give more route choice to the first control (current #2) and not cost much.
Leg 3 - like many of the legs on this course there is an "obstacle" on the straight line (in this case a patch of green) creating decent route choice.
Leg 5 - I agree with TM that this maybe a bit easy at the end. But it still has good route choice and decent navigation requirement at the beginning. Perhaps a leg I'd want to look at for potential to improve.
Leg 6 - I really like these with options to drop down then cimb, try to contour, or go up and then drop. All demanding concentration not to waste time/elevation/energy on the slopes
Leg 7 - I think a reasonably "gentle" way to deal with the chasm crossing - decent route choices and concentration required.
Leg 8 - Pretty nice with two options - one safe but through grreen (down re-entrant) and one more tricky but in white (drop then contour across in the white)
Leg 9/10 - I don't like this section for a number of reasons - 9 is pretty easy; 9 has dog leg, 10 is on too steep a slope. But luckily the course is too long (probably) and going from 8 - 11 is probably a pretty decent leg. So I would drop 9 & 10.
Leg 12 - we saw a similar leg in another course, but this one I think is an improvement because of the location of the start of the leg - that gives more route choice since the track on the right isn't so attractive and the go-past-13 route is good (and has lots of sub-options).
Leg 13 - like TM hints, this is kind of sucky. You basically turn around and go right back where you came from. Better to head NW from 12 and come at 13 from somewhere else.
Leg 14 - pretty lame. If 14-15 wasn't so interesting I'd drop 14. But even as it is, with the course being a touch long, and the 180 at #12, I think the focus should be on removing the 180 at 12 and perhaps giving up the cool 14-15 leg. Or maybe give up something a bit later in the course. This is the tough kind of decision that good course planners often face - which good legs do I have to give up ;-)
Leg 15 - really nice change of pace into the road section of the map. When compared to another course with the 3km long "easy" leg with great route choice, this one seems more acceptable to me since it is shorter, so less of a portion of the entire course.
Leg 17/18/19/20 - this seems the weakest part of the course with a lot of down the big hill then back up and a lot of fairly easy orienteering. I think it is a great idea to put some tough physical challenge at the end of a championship course as it tests fitness and determination - but this is perhaps a bit too much. Maybe just one climb would be enough? These guys running are your friends after all ;-) Definitely would suggest the course planner put a bit more effort into the end of the course.
Arena - nice, as I'd expect from an experienced planner!
Nice course - it would be fun to run it for sure, and very challenging in both navigation, fitness, and concentration
Is control 7 near the "tube slide" that Bruce Moore mentioned?
I don't see any option to 6 other than almost straight (assuming these are American rather than Norwegian woods)... in which case the control location is trivial, on the ridge. Now, maybe the intention is to make 5 and 6 extra easy so the physical 5-6-7 stretch will induce errors on 8 or 9...
Besides that, I mostly concur with TM.
Too much love given to the steep bits.