I've got some experience with both the RD9 and the BK9.
Pros & Cons:
Justin is a great guy who will go out of his way to be sure you're satisfied with his product. Camillus is all but out of business and many have had difficulty with warranty issues.
The Becker is full-on production and the fit and finish reflects that - nice and clean. The RD9, while not truly custom, are at least hand finished: Solid as a rock but not made to be pretty.
The RD9 would be, imho, more difficult to break than a Brute. However, realistically, you aren't going to break either one of them. Neither would leaving me feeling unprepared or lacking in a survival situation where a large chopper is required.
The bottom line for me would be which one I found more comfortable to use. While I think the Becker grips are ridiculously large on the small Crewman or Campanion, I think they are GREAT on the larger RD7,9 Brute and Patrol Machete. Many, many people don't like the BK grips at all - I'm NOT one of them.
The RD9 wasn't a comfortable grip for my hand. Nothing wrong with the grip - it just didn't fit my hand. It dug painfully into my little finger and felt a bit too narrow.... I think. Then again... maybe it wasn't too narrow but it never felt "right" to me. This isn't indicative of everything Justin makes; a 3V custom at Blade felt amazing. It was the same basic RD config (RD6) but the Markarta grips and polished blade just felt great.
So... my 2 cents and that's all it's worth: Get whatever feels best.