I think BJJ is much lower impact. Maybe they take it easy on me because I'm the oldest guy in the room. I know even the mild calisthenics at the beginning of practice nearly wipes me out, I'm in such bad shape! The folks are super nice as befits practitioners of "the gentle art".
My first BJJ practice I had to borrow an ill-fitting gi and everybody thought it was weird I was wearing wrestling shoes. I had to get permission to wear them because everybody else was barefoot. After the calisthenics the instructor started demonstrating a triangle choke (headlock to wrestlers) and choked out his partner! I couldn't believe it! I never saw a guy get choked out in wrestling practice (although I did choke out a guy with a perfectly legal headlock in HS on two different occasions). Also in BJJ you don't have to worry about back points! Like prostitutes, Jujitsuka do their best work on their backs.
Oh yeah, the best part is I'm better at taking people down than anybody in the room, even as a 60 year old! Seriously, didn't you just take to BJJ like a duck to water? I already know 90% of what they are teaching, just by different names.