I haven't really seen it.
I'd think others would post about it, too.
There's still enough momentum behind Java (and OpenJDK) that if there problems, people find them and fix them.
Whether they are in the JVM or in the Java Application or in the Java Applet.
I'd also even go so far to say that if there is a misbehaved applet or application, then the problem is with the applet/application, not the runtime. The JVM, for the most part has been pretty stable since 1.4
What brought me to Debian was one-stop shopping.
What brought me to SID was apt-get update && apt-get dist-upgrade.