Pros:
The best thing about this course is its setting. I have only played it in August, when the snow is gone from the mountains, but at 9000' in the Rockies, there are probably months when it is even more beautiful. The scenery around me took my mind off my score, which was fine, because just being there in the natural beauty throwing discs around was more fun than trying to set a personal best would have been.
The course is laid out well enough that it is not difficult to follow the flow of the course from basket to tee pad, even for visitors from out of state, and the baskets and pads are all in good condition. The pads are all concrete, and large enough for a tall player to feel comfortable on them, and the baskets, I believe, are all an older model of Innova Discatcher. I also appreciated the practice basket that is installed near hole #1.
The layout was also pretty good. Although there are no "signature" holes, there are no bad holes, nor any that seemed like a waste or misuse of the space. I hear the area has suffered from a plague of pine beetles that has killed off a lot of the forest, but I don't think this has negatively affected the Peak One disc golf course. The fairways were fair, and since there is virtually no undergrowth or "shule" on the course, you'll never find yourself "in jail" after a bad drive. This seems to me to make the course more forgiving than many others I've played, with the challenges on the course coming from distance, wind, and play between the trees, with less of a premium on keeping your drive in the fairway, and more opportunities to "save" a hole with a quality second shot.
The lack of undergrowth also makes it easy to find discs that leave the fairways, which is a very helpful feature for a course that has so many "blind" tee shots.
Finally, I found the course very easy to play at a fast pace as a solo player, with no backups at any holes, and the local players happy to let me play through when I caught them. I saw no litter, no rudeness, and no selfishness -- only friendly disc golfers enjoying the course. This is the way it should be everywhere, but since it isn't, it's is a nice treat to experience in Frisco.
Cons:
The course's biggest weakness is its tee signs. There is a tee sign present at each hole, but since each hole has at least two basket positions, and the tee sign only shows one distance, what you see on the sign may or may not be relevant. I suspect the tee signs all show distances to the "A" basket positions, but I couldn't honestly tell, since most of the baskets were in the longer "B" positions when I was there. Most of the baskets were not visible from the tee pad anyway, so your best solution is to scout the basket locations on foot, and throw by feel until you are familiar with the course. The difference in the "A" positions and "B" positions is sometimes way over 100', and it might add up to a difference of 1000' or more if the basket positions were all "A" vs. all "B", so it would be nice to get that second distance marked on the tee signs.
Another oddity about the layout, especially in the "B" positions, is that some holes seem to have no fairway to the basket. You have to throw blind over the tops of low-growing (young?) pine trees, and learn the direction to throw by experience. I was also a bit confused at times by the angle of the tee pad relative to the basket. It's impossible to aim concrete pads directly at two different basket locations, but there were a few pads that seemed to skew wildly off in an odd direction, not really at either basket location. I don't know if this could be corrected or not, but it ultimately didn't case me any serious problems, since the pads are wide enough to allow a diagonal run-up.
Other Thoughts:
At this altitude, I was afraid I would be sucking wind around the whole course, but Frisco is in a relatively flat valley among the mountains, so this was not a "ski slope" course that sends you up and down steep hills. A local player I met actually said it is converted into a cross-country skiing area during the winter, which should tell you what kind of elevation changes the course has: moderate hills, but overall on a fairly level plot of land.
I didn't suffer from altitude sickness, but the air is definitely thinner up there, so expect to be winded until you're acclimated to the altitude. Also it's a very dry area, so bring lots of water or sports drinks to stay hydrated, and wear sunscreen. I didn't take the advice seriously enough that you get sunburned more easily at high altitudes, and ended up with sunburned forearms. I'm okay, but don't be the guy that gets lobster red because you stayed out all day on a sunny day.
The elevation didn't seem to make my discs fly farther, but they definitely flew differently. My stable discs became overstable, my understable discs flew straight, and my overstable discs became virtually useless meathooks. On the other hand, the distance that the discs faded didn't seem all that far -- instead of fading way wide, they seemed to just drop out of the sky when they started to fade. The only way I could achieve a left-to-right curving flight (rhbh) was to throw my most understable discs with significant anhyzer; my Prodigy F7, my beat up Pro Katana, and my beat-to-silly-flippy Blizzard Boss were able to hold an anhyzer line, but nothing else in my bag would. I got the best results driving with the Katana, the Blizzard Boss, and my Star Valkyrie. Moral of the story: bring understable to stable discs, and leave the overstable discs at home. I think the thin air gave my discs less glide, but slowed their forward progress less, so the total distance on a good flight line was about the same as I'm used to at 1000' above sea level around Atlanta. You just have to go about getting your good flight line in a different way.
Something else to keep in mind is that the course is always windy, with ever-present strong, gusty wind on the holes by the lake, so bring your heavy, stiff, wind-fighting putters.