Ive found Hanna to be pretty good, even without p.o.p (i bought a P04 checked from a MASA member, who declined to mention there were no vials inculded, i contacted Hanna who sent me some free of charge).
@Sean81 - sorry for the late reply bud, i just checked the expiry and its dated 2.2015! Which is funny because id been using them right up until i shut my tank down in June (this this year). If you want them to test with etc, send me a self addressed envelope and ill pop them in the post for you :)