Funny, the only triple square I have damaged is a Snap On. It didn't break, but it's a bit twisted. Yes, I used an impact on a non-impact tool.
I have a Koken set and it's done most everything I've asked of it (no impact). If I was starting over I'd probably get one stubby set and one long set. Sometimes the Koken's are too fat/tall, other times they're too short. It's sort of like starting with semi-deep sockets. Great most of the time, but they can't replace regular and deep sockets now and then.
Metalnerd also makes some nice sets and and I have some of the specialty bits to supplement my Koken set. They also have specific impact rates bits.
I wouldn't lose sleep over the difference between Koken/Vim/Metalnerd. I think they're worth the small step up from the random rebranded stuff you see a lot off. If you're in a shop you could get by borrowing one if you break a cheap bit. If you're at home with your car half apart you might be SOL.
Sent from my iPhone using Tapatalk