Pros:
Parking Lot 'C' seems to be the fastest way to get to and from the course. Driving in on Monday at noon in July, this is about the most crowded I've seen a park on the weekday, nearly every parking spot on every lot was taken. If I had more time, I would have liked to take in the environmental center and such, but now that I know about it, next time.
On the DGC itself, it was empty of players until I got to #17, when I heard the basket rattle on nearby #7. It's the shortest 18er I ever played, just averaging under 200' (197.4' to be exact) which is about the median as well. Longest hole clocks in at 246'.
Despite that, I never got bored. This is like an 18er that strips aways the drives, leaving you only with heavily technical approach shots and the putts. Elevation plays a pretty heavy role here and it probably had every common variation in flat but also downhill, uphill, and some sideways. If that sounds appealing, Haverford Reserve is exactly for you.
This course also plays the basket-on-the-right card pretty heavily and often and what's not on the right is typically straight on. I can only recall one that ended on the left, maybe there were several. Hell, I think LHBHers and RHFHers get the short end of the stick fairly often on courses, so good for them.
Has good tee signs, baskets, navigation was generally not a problem, etc.
Like Hyoomac pointed out, #18 was a total surpise and a saving grace for being memorable. I threw it as softly as possible, and it still sailed way past, plus I had to run right after from the tee to the edge to even see where the disc generally went. A spotter helps here.
I had a good time overall and will have a better time next time now I know the pitfalls.
Cons:
The biggest cons I found was #5&6 which are disc traps in growing seasons. They are the only two open holes around. #5 starts out in a forest tunnel out into open, while #6 was lined on the left with forest edge and a basket left. Both have very narrow fairways right now, cut amongst masses of growth which might as well be water.
A lot of this isn't simply growth that can be swept aside browsing for lost discs quickly, but are rather tangled bushes voraciously that eat and stubbornly hide anything tossed their way. Paired with lots of virginia creeper and poison ivy. No thanks. On my tee off I hit a branch and the disc played hide&seek for a good 10 minutes, despite seeing exactly where it went. Being too dumb to get the message, I lost that disc for good with my second bad throw. SKIP RECOMMENDED around summers unless you're throwing good that day and sure of your aim.
Surprisingly for such short distances, there were plenty of times I could not see the baskets from the tee whether from trees or trajectories. The Disc signs were well made but I don't think it always told the entire story for some reason, especially when elevation was involved. First time I ever wished for topographical lines to be on a DG map.
Hand in hand came some trajectories I'm not sure are realistic. Like on #1, I was expecting the basket way more to the left than it actually was just from the way the tee was pointed and how the fairway seemed to be going. I'm not really sure if exaggerated 'S' curves in just 180' in some of these fairways are all that realistic. I would normally say not to bother bringing drivers here, I didn't, but I think the extra fade on some of them would have helped sometimes.
Navigation is easy when the baskets are clustered together but #4 to 5, 9 to 10, and several others had quite long jumps. There are sometimes white signs with tiny lettering on trees pointing out the next tee. The trail right before #18 could have used a sign as well.
Many of the tees are rather short, framed in wood and covered in artificial turf, are already rather lumpy. No big deal on standing throws at these distances, but I wouldn't want to running start on them.
Outside of #18, I don't remember most of the other holes a day later. It's a solid course for its purpose but, as is, shouldn't be anyone's far-away destination course.