Pros:
Setting - Conifer, CO is an absolutely beautiful area. The terrain is exceptional for disc golf. Areas underneath trees are really cleared out well so lost discs will not be a major issue. The air is thin and crisp. It smells like pine trees. It's about as nice of a setting as there is for disc golf.
Design - It's simply a great design. There's no way to describe it better. Elevation is used well. Right, left, long, short ... it's all there.
Tee Signs and Navigation - Very easy to get through this course, even for a first-timer.
Cons:
The major cons have already been stated in detail by others.
1) Some shaky natural tee pads still in use.
2) Extremely long walk to #1 and back to parking lot from #20.
Other Thoughts:
I didn't put as much effort as I usually do into the pros and cons because I wanted to try something different in this section. Once a course has SO many reviews, it is boring to restate a lot of information. Having said that, I've had the privilege of playing some of the highest-ranked courses on this site, so I'll give you my opinion on how BR stacks up against them. Some will hate this method, but others may appreciate the additional information.
Flyboy: BR is not quite as "epic" as Flyboy. Having Kelly at Flyboy to escort you around is great. BR also really doesn't incorporate water hazards into the design.
Flip City: Flip City is one of my all-time favorite courses. If BR had concrete tees on every hole, it would be better than Flip. Again, just my opinion.
Highbridge Courses: BR compares the most to Granite Ridge in my opinion. They are very similar in terms of length and design. BR probably has slightly more elevation used in the design. Granite Ridge is the only 5.0 in my book at the Highbridge complex. With concrete tees, BR would be right beside Granite Ridge. Blueberry and Gold are great courses, but BR is better in my opinion due to maintenance, tee signs and other navigational issues.
Blue Ribbon Pines: BR is what Blue Ribbon Pines should be ... an amazing 20 hole course. Blue Ribbon Pines has a number of filler holes to go along with about 18 great holes. BR has trimmed the fat. There are no filler holes here. Tee signs are also much more informative.
Phantom Falls and Magic Meadows: Both are great courses, but I think BR is superior based on the amount of land available for use. BR is on a large plot of land and uses it very well. All of these courses should be played when in Colorado though.
In essence, Beaver Ranch is one of the Top 10 courses I've played...and I've played a few now. I don't throw around the famed "5.0" very often, but if Beaver Ranch had 20 concrete tee pads and something could be done to limit the need for a long hike to and from the course, this course would qualify as "Best of the Best". It's that good.
As far as traditional "Other Thoughts" for the review, the first 3 holes play significantly uphill. They will wear you out. After that point, the hike becomes much more bearable. For those not used to the elevation, take your time and bring a lot of water. Water will neutralize the effects of the thin air, so if you usually drink 2 nalgene bottles of water per round, pack a third.
I have heard the course can be crowded at times, but we played on a Monday evening and it was really pretty empty.
There is an extra hole, not sure if it's always used for tourneys or whatnot, but it plays over the small creek into an open field and functions as a closing hole. It's really easy and may make you feel better if you've had a tough round. Otherwise close with #20 which is a pretty awesome finishing hole...steep downhill through a tunnel and into a grove of trees. Very cool.
Also, for out-of-town disc golfers, pack a pair of long sleeves or light jacket if playing in the early evening. Even though you're only about 45 minutes outside of Denver, the temperature drop can be upwards of 20 degrees. I know we went in the middle of July and temps in the mountains were in the 50s. I'm sure the locals are used to the weather, but if you're traveling from afar, just be aware.
Beaver Ranch is an awesome course. It is definitely worth the trip to play, and not to be missed if you're in the Denver area.