As I wash my hands gratefully clean of the application process, I want to quote my thesis advisor, who sits on the admissions board of a Top Five Program:
"The writing sample is 99% of the criteria used in making these decisions."
Whatever concerns you have about the GRE, the recs, the annoying essays, etc., it's always, always, always going to come back to that sample. Focus on ironing out those samples before you study for that GRE, dig?
Good luck all,
Prolific in Prague