I would have loved to do lots of this BJJ as a younger lad. As it is, I pick and choose these competitive venues very thoughtfully.
When I was younger, aikido with a Goju guy who came from special forces was my view of this venue. Jiujitsu of course is the antecedent to aikido. I did plenty slamming around and got to be slammed. I got a shoulder separation, tore someone's knee (accidentally), broke an arm (accidentally), etc. We were in a mixed group of dans doing cross training, and none of us knew how to take it easy.
When I decided to do aikido in Maryland with Clyde Takaguchi's group, I was thankful for my karate base. Whenever some A-hole thought he was going to take out his frustrations on me, I always had a few tricks up my sleeve that stopped things dead in their tracks. It only took a few times to get respect...

Most of course were good, and had a lot to teach me.
Come to camp and work with Joe Pomfret, Ian. Even I get in there and allow myself to get my butt whooped by Joe. Fun stuff...
For martial arts in general, I've never been afraid to work with the very best. I'm never fearful of sparring champions, ring fighters, etc., etc. It's the insecure A-hole with a chip on the shoulder that you need to break bad with to preserve your health. It's always good to have that ability - and the will to use it when necessary - in your back pocket.
- Bill