Yeah, completely obsoleted by 300blk. But definitely fun.
Maybe. Although I was watching Gun Stories with Joe Montegna last week and they had that APC9K thing that the .mil just "bought" for subgenus. THAT looked interesting. It APPEARS light. (Although a quick check online says it's in MP5 weight class.). Suppressor ready. I could see that giving any of this a run for it's money.
But I agree about 300BLK. You can run it supersonic and have a massive punch OR you can run it subsonic, have it relatively manageable and more oomph than a 9mm.
I've yet to bring my 300BLK upper to the range. Stupid of me, I know.