Sean: I love both courses and look forward to visiting both again. Yet I am not sure I would place either in a list of my top 25 links courses. They are too wild for a lot of people.
If I had to pick one telling difference between the two, my impression (from walking Brora, I was not able to play) was that Brora restricted long driving on a lot of holes, with interrupted fairways at 230-260 yards off the tees, whereas at Pennard the long hitter can pretty much always hit away. I know those outward holes at Brora were into a strong prevailing wind when I saw them and I would not have been hitting irons off the tee that day, but it could be a problem in some conditions, and if so then Pennard would likely get a higher ranking from the majority of low markers.