Out of the numerous pros to consider with Beaver Ranch, I believe the actual course design and stunning baskets should get top mention. First, the course was masterfully designed with multiple layouts for every hole. Whether is the alternate tee placements, or up to five alternate pin placements as on #17, the shots selections are always fresh. Note that #17 had actual pins in place at positions C and D, so my suggestion is throw two since I believe this is a signature hole where the stunning 75'-100' elevation drop to open meadow below deserves a minimum to two tosses. Hole #16 currently has two pins in now as well.
Besides the superior design, honorable mention goes to the discin baskets with their angled copper ring and white hue. They're easy to spot from a distance contrasting perfectly with the surrounding greenery, and they're simply beautiful. The park has also gone to the effort to posting tall flags on most pins to help with spotting the hole from a distance. I echo DGTourist's comments that the bar seems more inviting with it's inward angle making that mental "clang" we all hear in our minds before putting on a DisCatcher basket seem to disappear.
Some other pros to consider (besides scenery you can't experience most anywhere else in the country) are the moves the park is taking to improve on their course. Steps are currently being installed in lower portion of hole #1 making the insane climb a little easier. There is a bathroom facility by #14 pin off the Blackhawk trail for those needing a break, and most pin locations have a good amount of mulch surrounding them to help prevent erosion and the pool of mud that would gather after a rain.
Finally, it's also worth it noting that if you're not dead after taking on this superior course,
Phantom Falls - a private 30-hole elevation monster is right down the road. I had the privilege of experiencing both courses in the same day, and topped off the ultimate disc golf experience with some tasty wings at the Wing Wagon in Conifer.
BEST HOLE/S: #1; #17; #20