Advantage-you'll get a cartridge with considerably more case capacity

Disadvantage-only Bertram makes the brass. Over the years, both BeLL and Bertram were the only ones forming hard to get brass for the not so common calibers. Bertram seems to be the major supplier but their quality control sucks. I got some brass for a 475 J No 2 years ago to reload for my buddies dad and found that over half were AFU. Their refund policy also sucks.