Pros:
Uniquely situated on top of Grouse Mountain, this is really a special course in the Vancouver area. Spectacular views and a great variety of shots really make this a fun course to play.
Excluding a few holes at Passive Park in Langley, most of the courses in the Lower Mainland (Vancouver metro area) offer very few long, open shots, and it's a really nice change of pace to have those shots here. Couple that with a lot of change in elevation and you've got a really challenging course.
The front 9 is accessible to new players and those who may be visiting the mountain not planning on playing disc golf (I'd highly recommend the newly installed "family tees" to those who have never played before). Those holes offer a variety of shots going uphill, downhill, and a few relatively-flat traverses.
However, the back 9 is really where the course earns its challenging label.
Starting with the wide open (when the grass is low) and downhill, 818 ft #10, the rest of the course is much longer and less tolerant of mistakes. After hole 12, the lowest point on the course, you begin your way back up to the top of the course, and it really tests your ability to throw uphill and navigate narrow fairways.
Considering that 2014 is only the second year of the course's existence, the maintenance and upkeep on such rugged terrain is commendable. Tee signs, trails, and the course map all make navigating the course easy for first-timers, though playing with someone who has played before can be really helpful for the playing side of things.
Also, being able to grab a beer at the chalet is a great way to finish up a round, or recharge for round #2, if you're feeling up to it.
Cons:
Inherent with a location on top of a mountain that functions as a ski mountain in the winter, there are certain challenges and lacking amenities that make the course a bit of a slog at times. I would budget about 3 hours per round.
The gravel teepads can be stumble-inducing when you're trying to rip out a strong drive. Would like to see concrete or something else.
As other reviewers have mentioned, it would be nice to have benches or another way to rest throughout the course. It's quite the workout, and once you start climbing back uphill after 12, you're gonna want to rest. So find a good rock, or just plop down on the ground.
The rough here can be really rough and the chance of losing a disc at some point is relatively high. The best way to avoid this is using spotters (primarily on the tee shots for 10, 11, 14, and 16) and playing a bit conservative, especially if it's your first time playing it. The woods, bushes, and uncut grass are *very* thick, so if your disc goes in there, make sure to carefully make note of the branch or bush where it entered, you'll save yourself a lot of scratches and frustration.
Also, conditions on the course are extremely variable with the weather. A pleasant, but cloudy day down below in Vancouver can be a fogged-in, rainy nightmare at Grouse. Oddly enough, temperature inversions in the early fall can create the opposite, a cold rainy day in Vancouver can be a clear sunny day on Grouse. Thankfully you can actually see the course from miles away (if unsure ask a local) and they have a live webcam on their website, so make sure to check the weather before you head up.
Unfortunately, the big con is the cost. It's expensive (something like $40) to ride the gondola up, and $10 to ride down if you're in shape enough to hike up and then play a round. However, the ride is a lot of fun, and there are other attractions at the top, though they may be a bit tourist-trappy. See Other Thoughts below for tips on this front.
Other Thoughts:
Most of the locals that play the course regularly have a Grouse season pass that grants up to four of our guests half-priced admission. If you're visiting and want to play up at Grouse, post on the discbc.com tagboard or some of the local club facebook pages (my club, Van City United, has worked well) to see there's anyone going up at the same time as you that you could tag along with.
If you're driving to the mountain, know that you have to pay for parking at the base. However, there is a free shuttle that leaves from Canada Place in downtown Vancouver and only takes about 20 minutes to get to the base. If you're staying in the city, I highly recommend the shuttle. Hours of operation vary seasonally, so I'd check the website. Unfortunately it doesn't run after 5:30, so if you're up there later you can take the bus/ferry back, but that takes about an hour or more.
Make sure to pack some snacks and plenty of water. You can refill water bottles at the chalet, but logistically this only can be done before or after a round. Food is available at the chalet as well, but it's pretty pricey.