So far the end cap has stayed on. I watched a lesson my son took and the bat has pop. He says the sweet spot is a lot bigger. If he doesn't hit it right on the center of the sweet spot the ball still goes. Sounds like a BESR. I asked the company if they had fixed the end cap problem and the said they did. Of course, what else would they say... but so far so good. He will be playing fall ball so we will be able to tell more later.