I guess you have the same problem I had, regarding the Content Assist in Eclipse took several seconds to minutes to show a result once coded.

This made me not only frustrated, but it simply was not possible to code with constant interruptions.

One way that reduces the time, is to disable “JAX-WS Propasals” found in “Windows Preferences” -> “Java” -> “Editor” -> “Content Assist” -> “Advanced” and uncheck “JAX-WS “simply.

Hope this tip helps.