I tried it for a time. It initially gave me a headache, but that went away with time. I lost a lot of weight on it - had no appetite at all. Overall, I'm not sure that it helped, although it did seem to help a bit with inflammation (redness in face lessened, less dry eye, etc.)
It does increase bleeding tendency, and many ME patients have elevated tPA to start, and sometimes abnormal clotting and/or fibrinolysis, and antiphospholipid syndrome is not uncommon (although I don't have it). If you have any tendency to bleed you need to be careful - and INR would be sensible to check in advance as well as some basic measures of fibrinolysis - including d-dimer/FDP and t-PA.
In general, I think it's a pretty safe med and a decent inflammatory. I'm not sure it really helps a lot in ME though - I've yet to hear of it really having a great effect in anyone.
I wonder if the headache is a general effect or something particularly common in ME.