In the years of his work, the movies were fair to great, but his performances are always above the standard. Phillip could envelop a character. You don't watch Phillip playing a character,
but you watch Capote,
you watch Joe from State and Main,
you watch the CIA operative Gust in Charlie Wilson's War,
and you watch The Count in Pirate Radio.
What makes Hoffman's characters so unique is his interpretation of the screenwriter's vision. Hoffman added depth, and makes the performance richer, yet he doesn't need to chew up the scenery in order for you to remember the scene. A particular look or turn of phrase captures the character.
When I am screenwriting, I know my writing doesn't mean as much without the performance of the actor playing the roles I write. I write for them as much as the audience.
I am so sorry he left us before his time. I write for actors, and he was one of the very best.