Strong was excellent at ASU, but he's never made much of an impact in the NFL... it hasn't helped that he's been playing WR with the QB dumpster fire in Houston the last 2 years. He came into the league at 6'2, 217lbs with a 4.44 40 & 42" vertical leap so he has the physical traits teams want. At ASU, he was great at catching back shoulder passes on the sideline & was a good 50/50 target. He's not the quickest guy off the line, but he has long speed & has good strength to get off press coverage.
The knock on him was that he didn't run great routes & didn't get good separation at the college level so that stuff is even harder to do in the NFL. I don't know how good his football IQ is either. He sounds a lot like Michael Floyd... Strong also faced a 1 game suspension for substance abuse. Sources in Houston are saying that his release doesn't have anything to do with more substance abuse problems & it's 100% football related.