IME, the strengths were primarily that it was Java+. However, the Java-heavy organizations that might most benefit from it tended to also be the most averse to change. Changing "that much" for "only" incremental change wasn't worth the risk for risk-averse companies. The companies that weren't risk averse tended to try it, but also go outside the JVM altogether when appropriate. So... in a way it was too good at just being a more useful Java, but that wasn't enough for Java-heavy shops.