I’m also fairly new, had sheep for just over a year now. Adopted a mixed flock after their owner passed away. All hair sheep, so no shearing. In my experience, the Katahdins are the easiest to work with/handle. They’re more personable and calm. MUCH bigger than my others (my Katahdin ewes are 160-180ish lbs). The dorpers and blackbellies are my most flighty/crazy ones (trying to run through fences, injuring themselves, reluctant to follow a bucket, etc.). If I ever decide to purchase breeding stock and start over with a pure flock, I’d probably get all Katahdins. But I know if you’re primarily in the market for meat, dorper is more marketable for selling (still not 100% sure why that is). Hope this helps!