I have 3 Keltecs. Two sub2000's and a PMR30. They have been perfectly reliable thus far. The PMR has 850 thru it without a hiccup. I have had one ejection problem with the 9mm sub2000 in 400 rounds and zero problems with the 40 cal sub 2000.I have a little over 1200 thru the .40 cal. The one issue was my fault and not the gun. I was shooting from the bench and the charging handle got hung up on the shooting bag.
I have had more issues with some other guns. No manufacturer is immune to letting poor quality get out of the door now and then.
YMMV