I'm not sure how much this diminishes my credibility as a geologist, but I do not own a Brunton compass.
(photo from here)
What distinguishes a Brunton (sorry, pocket transit) is that you can measure dip angles and compass headings with remarkable precision, it's small (if not light), and it's bulletproof. The ones we used in college and grad school had been manhandled by generations of students and worked fine.
Last time I needed to determine fracture orientation in the field, I had to scrounge around for a pocket transit that I could borrow from someone else, since my organization didn't have one. When I started asking around, I found that about 20% of geologists had
their own pocket transit. My sample may be biased low, because these
were the people who knew I was looking to borrow one. Other owners may
have kept quiet because they weren't willing to share an admittedly expensive gizmo.
The pocket transit I used worked out fine, but since I was using a personal, very expensive item, I was petrified of dropping it or scratching the mirror - a real possibility, considering the rocks I was scrambling about on. I've been keeping an eye on eBay - they turn up regularly at prices ranging from less than $100 for dusty old finds to $700 or so for unused ones.
If I were a structural geologist, I'd definitely have a pocket transit. But I rarely need to go out and assess outcrops. Readers, if you do structural-type stuff a lot, do you still use a trusty 50+ year old product, or do you have something newer/fancier/better?